A TEXT-BOOK 



REC 

MAY 14 1898 



OF 



Dental Pathology and therapeutics, 



INCLUDING 



PHARMACOLOGY. 



BEING 



A TREATISE ON THE PRINCIPLES AND PRACTICE 
OF DENTAL MEDICINE. 

FOR STUDENTS AND PRACTITIONERS. 



/ 



BY 



HENRY H. BURCHARD, M.D., D.D.S., 

SPECIAL LECTUEER ON DENTAL PATHOLOGY AND THEEAPEUTICS IN THE 
PHILADELPHIA DENTAL COLLEGE. 



ILLUSTRATED WITH 388 ENGRAVINGS AND 
TWO COLORED PLATES. 













LEA BROTHERS & CO., 

PHILADELPHIA AND NEW YORK. 

1898. 



ONE COPY RECEIVED 



^ 

M 



&° 



7U7 



Entered according to Act of Congress in the year 1898, by 

LEA BROTHERS & CO., 

in the Office of the Librarian of Congress, at Washington. All rights reserved. 










\ 



WESTCOTT & THOMSON. 
ELECTHOTVPERS. PHILADA. 









DEDICATED TO 
G. V. BLACK, M.D., D.D.S., D.Sc, 

TO WHOM RATIONAL DENTAL PATHOLOGY OWES SO MUCH, 

AND TO 

DR. EDWARD C. KIRK, 

TO WHOM DENTAL SCIENCE OWES MUCH AND THE AUTHOR OWES 
MORE THAN HE CAN EVER REPAY. 



PREFACE. 



This volume is designed as a text-book of the principles and prac- 
tice of dental medicine for the use of students, and as a reference work 
on applied special pathology and therapeutics for the use of dentists. 
Accepting the dictum of the advanced teachers of the day, the writer 
believes that an entirely rational system of dental medicine can have 
but one basis — namely, the same principles which underlie general 
medical and surgical practice. The book represents, therefore, an 
attempt at formulating, from data obtained from every available source, 
a system of dental pathology and therapeutics of which the several 
parts shall be in harmony with one another and also with the several 
collateral sciences involved. The impulse prompting the work was no 
desire to multiply books, but arose from a conviction expressed by 
many teachers, that such a volume is needed by students, practitioners, 
and teachers. 

The extent and scope of references may be only partially seen in the 
numerous foot-note references, space limitations precluding any ex- 
haustive bibliography. 

It would be unjust, however, to omit this opportunity to credit two 
investigators without whose researches this volume would have been 
impossible : Professors G. V. Black and W. D. Miller, to whom fre- 
quent and specific references are made. 

The immense development of modern dentistry has brought with it 
a more rational and convenient grouping of its subjects. The American 
Text-Books of Operative and Prosthetic Dentistry have already won 
acceptance, each in its own field. They leave untouched a range of 
subjects which are naturally cognate, and hence are most advantageously 
taught in conjunction — namely, Dental Pathology,' Therapeutics, and 
Pharmacology. The fitness of this grouping is manifest. 

Special thanks are due the publishing department of the S. S. White 
Dental Manufacturing Co. for their liberality in furnishing illustrations ; 



6 PREFACE. 

thanks for cuts are also tendered G. V. Black, J. S. Marshall, J. L. 
Williams, Win. Wood & Co., and P. Blakiston, Son & Co. 

The author tenders to Lea Brothers & Co. his grateful thanks for the 
more than liberal spirit exhibited by them in the making of the book ; 
from beginning to end their course has been one of great courtesy and 
unbounded generosity. 

H. H. B. 

April, 1898. 



CONTENTS. 



SECTION I. 
GENERAL PATHOLOGY. 



CHAPTER I. 

PAGE 

GENERAL PRINCIPLES 17 



CHAPTER II. 

CAUSES OF DISEASE, GENERAL AND LOCAL ............ 28 

CHAPTER III. 

BACTERIOLOGY, WITH SPECIAL REFERENCE TO DENTAL PATH- 
OLOGY AND THERAPEUTICS 37 

CHAPTER IV. 
DISTURBANCES OF NUTRITION: ATROPHY, DEGENERATION, NE- 
CROSIS, HYPERTROPHY, TUMORS 51 

CHAPTER V. 

DISTURBANCES OF THE VASCULAR SYSTEM 69 

CHAPTER VI. 
INFECTIVE INFLAMMATIONS: SUPPURATION, ABSCESS, FEVERS, 

SEPTICAEMIA, AND PYAEMIA 89 

7 



8 CONTENTS. 

SECTION II. 
ANATOMY AND DEVELOPMENT. 



CHAPTER VII. 

PAGE 

THE DEVELOPMENT AND STRUCTURE OF THE JAWS AND TEETH 101 

CHAPTER VIII. 
THE SURGICAL ANATOMY OF THE TEETH 141 

CHAPTER IX. 
DENTITION: ITS PROGRESS, VARIATIONS, AND ATTENDANT DIS- 
ORDERS 180 

CHAPTER X. 

MALFORMATIONS AND MALPOSITIONS OF THE TEETH 206 



SECTION III. 
AFFECTIONS OF ENAMEL AND DENTIN. 

CHAPTER XI. 

AFFECTIONS OF THE ENAMEL 243 

CHAPTER XII. 

DISEASES OF THE DENTIN 260 

CHAPTER XII (Continued). 
DENTAL CARIES : . 264 

CHAPTER XIII. 

DENTAL CARIES: ITS CAUSES AND CLINICAL HISTORY 273 

CHAPTER XIV. 

DENTAL CARIES: PATHOLOGY AND MORBID ANATOMY 290 

CHAPTER XV. 

DENTAL CARIES : DIAGNOSIS, SYMPTOMS, AND PROGNOSIS .... 304 

CHAPTER XVI. 
DENTAL CARIES: THERAPEUTICS AND PROPHYLAXIS 313 



CONTENTS. 

SECTION IV. 
DISEASES OF THE DENTAL PULP. 



CHAPTER XVII. 

PAGE 

CONSTRUCTIVE DISEASES 327 

CHAPTER XVIII. 

DESTRUCTIVE DISEASES OF THE DENTAL PULP 341 

CHAPTER XIX. 
CHRONIC DEGENERATIONS AND DEVITALIZATION OF THE PULP . 362 

CHAPTER XX. 

GANGRENE OF THE PULP . . . . ■ 381 



SECTION V. 
DISEASES OF THE PERICEMENTUM. 



CHAPTER XXI. 

SEPTIC APICAL PERICEMENTITIS (ACUTE) 393 

CHAPTER XXII. 
SEPTIC APICAL PERICEMENTITIS (CHRONIC) 407 

* CHAPTER XXIII. 
NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS 423 

CHAPTER XXIV. 

PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN . . 444 

CHAPTER XXV. 
PYORRHCEA ALVEOLARIS . . 459 

CHAPTER XXVI. 

DISEASES OF THE PERICEMENTUM BEGINNING UPON A LATERAL 
ASPECT OF THE TEETH 477 



10 CONTENTS. 

SECTION VI. 



CHAPTER XXVII. 

PAGE 

DISEASES OF THE DECIDUOUS TEETH AND THEIE TEEATMENT . 491 

CHAPTER XXVIII. 
REFLEX DISORDERS OF DENTAL ORIGIN 500 

CHAPTER XXIX. 

INFECTIONS OF AND FROM THE MOUTH, AND STERILIZATION . . 51i 



SECTION VII. 

DENTAL PHARMACOLOGY AND DENTAL MATERIA 

MEDICA. 



DENTAL PHARMACOLOGY . 529 

DENTAL PHARMACOPCEIA 545 



DENTAL PATHOLOGY, 
THERAPEUTICS, AND PHARMACOLOGY. 



SECTION I. 

GENEKAL PATHOLOGY. 



CHAPTER I. 

GENERAL PRINCIPLES. 

The study of dental pathology and therapeutics embraces a con- 
sideration of such principles of general pathology and therapeutics as 
find application in the practice of dentistry, and in addition implies 
and requires an exhaustive investigation into the modifications of these 
general principles growing out of the peculiarities of anatomical struc- 
ture and the functions of the parts included in the field of operation. 
There is, perhaps, no aspect of surgery in which these modifications of 
treatment, due to anatomical peculiarities, are more marked than in 
dental therapeutics. 

A consideration of the special practice must, however, be preceded 
by a study of the general disease-processes which affect the tissues of 
the body ; so that a special application of the knowledge thus gained 
may be made to render clear the nature of dental diseases and the 
rationale of their treatment. 

The word pathology is derived from the Greek pathos, disease, and 
logos, a treatise or discourse. Applied in its general sense, it includes 
a study of the natural history of diseases, their causes, progress, phe- 
nomena, and terminations. The word therapeutics is derived from the 
Greek therapeuein, to take care of, meaning the measures adopted to 
remedy or remove the changes induced by pathological processes. 

Pathology, as has often been stated, cannot be pursued as an inde- 
pendent study, for it is but an expression of other collateral sciences. 
It is a perversion of the processes found associated witli what are 
termed living bodies ; in its full and philosophical sense it is morbid 
biology — an altered physiology. It follows, therefore, as a corollary, 
that an exhaustive familiarity with the contemporary state of the science 
2 17 



18 GENERAL PRINCIPLES. 

of physiology is necessary to a clear comprehension of the nature of 
pathological processes. The more minutely an investigator proposes to 
examine into pathological states, the more extensive must be his parallel 
knowledge of physiology. While many phases and features of path- 
ology may be grasped by a student of but two courses, there are 
problems in modern pathology that test and exceed the resources of 
the veteran of the physiological, chemical, and pathological laboratory. 

Whatever field of medicine or surgery may be under systematic 
exposition, its study is made more clear by turning to and determining 
the nature of its logical basis, and proceeding from that as a fixed point. 
While it is true that pathology is by no means an exact science, for the 
reason that its mother science " biology " has not yet achieved that posi- 
tion, it is indubitable that year by year it increases in the measure of 
its exactitude. It is relatively a speculative science when compared 
with such a science as chemistry, which begins with an approximately 
fixed unit, the atom, and has, therefore, a corresponding stability of 
superstructure. A true, exact science, as mathematics, begins with 
a fixed and unchangeable unit, and is therefore absolute. 

The unit of the physiologist, and consequently of the pathologist, is 
a complexity in itself; it is a substance called protoplasm, of which our 
knowledge is imperfect and relative ; it follows, therefore, that sciences 
based upon such a unit will be susceptible to changes and alterations until 
the knowledge of the accepted unit is as complete as the knowledge the 
mathematician has of his unit. 

A contemporary philosopher has said that the standing disgrace of 
the science of chemistry is that it has not yet given an analysis of 
protoplasm. Protoplasm, so far as present knowledge permits a state- 
ment, is a viscid substance, which under certain conditions exhibits a 
sequence of phenomena which the physiologist calls life. Its chemical 
composition is very imperfectly known ; indeed, the only means 
available for its chemical analysis are such as destroy the identity 
of the substance. More than this, a subtle change occurs with the 
cessation of vital activity ; so that in all probability an analysis of 
dead protoplasm would not represent the composition of vital pro- 
toplasm. As set forth by O. Hertwig, 1 "we must regard protoplasm 
as a morphological, not a chemical conception ; " " it is not a single 
chemical substance, complex in composition, but is composed of a 
large number of different chemical substances which we have to pict- 
ure to ourselves as most minute particles united together to form a 
wonderfully complex structure." " Protoplasm cannot be placed under 
different conditions without ceasing to be protoplasm, for its essential 
properties in which life manifests itself depend upon a fixed organiza- 

1 The Cell, 1895. 



BASIS OF PATHOLOGY. 19 

tion." l Huxley has well termed the substance " the physical basis of 
life." The nearest approach to a chemical conception of the substance 
is that it is a collection of proteids ; and of these substances our knowl- 
edge is very imperfect. They consist of carbon, hydrogen, oxygen, 
and nitrogen, combined with sulphur and phosphorus in enormous mole- 
cules. It is known certainly, however, that protoplasm does not behave 
as a fixed chemical substance. 

As studied by the physiologist and pathologist, observations as to its 
properties are made in defined masses of protoplasm, which exhibit the 
sum of phenomena called life. A simple mass of protoplasm is studied to 
determine, as far as possible, the ultimate phenomena relating to vitality. 
For this purpose an amoeba, the anatomical equivalent of a white blood- 
corpuscle, is placed under conditions which permit of close and con- 
tinued observation and where the condition of its environment may be 
altered to study the effects of such alterations upon the vital processes 
of the cell. The study of collections of cells is a secondary pursuit. 
While, as has been stated, protoplasm, or contemporary knowledge of 
it, is the basis of the sciences of biology and pathology, the actual unit 
of the sciences is the cell. All reasoning proceeds from this basis, that 
the ultimate phenomena of life are expressed in cell-life, so that the 
properties and functions found associated with cells are the underlying 
data of pathology. 

If a drop of water be taken from the sides or bottom of an aquarium, 
placed on a slide and covered with a cover-glass, and then placed under 
a microscope with, first, a J" objective, there will be noted at some 
portion of the fluid a small transparent mass having the appearance of 
a colorless fragment of jelly ; this is an amoeba. The outline of the mass 
may have almost any form. At some portion there will be a defined 
and easily distinguished spot, the nucleus ; at another point a vesicle 
is seen ; the body of the amoeba appears to con- 
tain numbers of fine granules. The nucleus ap- 
pears more markedly granular than the body of the 
amoeba. If kept under observation, the amoeba will 
be seen to change its outlines ; at one or more, and it 
may be in several places projections like blunt arms 
or feet are seen to be extending from the amoeba (see 
Fig. 1). On account of their appearance they are 
called by the physiologist pseudopodia, from pseudo, 
false, and pous, a foot — false feet. These changes of amreba p^lseudo- 
form are much varied (Fig. 2). The cell has, there- podia; v, vesicle; n, 

n ., n -, . . n ... nucleiis. 

tore, the property of altering its form — i. e., it has 

contractility. If the temperature of the slide be raised, the movements 

1 The Cell, 1895. 




20 



GENERAL PRINCIPLES. 



of the cell become more rapid, and if raised to a temperature of 55° C. 
the cell contracts in a round lump ; it responds to stimuli, and has there- 
fore the property of irritability. 



Fig. 2. 




Amoeboid movement of a white blood-corpuscle of man ; various phases of movement. (Klein.) 

When certain solid substances contained in the water come in con- 
tact with the amoeba, the latter is seen to flow around and engulf 
them ; as is shown in Figs. 3 and 4, where the analogue of an amoeba, a 



Fig. 3. 



Fig. 4. 





Leucocyte of a frog from the neighborhood of 
a piece of the lung of a mouse infected 
Avith anthrax, about forty-two hours after 
the piece of lung had been placed under the 
skin of the frog's back. The leucocyte is 
in the act of eating up an anthrax bacillus. 
(Brunton, after Metchnikoff.) 



The same leucocyte a few minutes later, after 
it has completely enveloped the bacillus. 
(Brunton, after Metchnikoff.) 



leucocyte, has taken in bacteria. After a time the ingested body is found 
to have disappeared ; it has been digested. Evidently the cell must 
produce a substance capable of dissolving some foreign substances — i. e., 



Fig. 5. 








Forms assumed by a nucleus in dividing: a, resting nucleus ; b, skein-form, open stage ; r, wreath- 
form ; d, aster, or star-form ; e, equatorial stage of division ; /, separation more advanced ; 
g and h, star and wreath forms of daughter-nuclei. (Reduced from Flemming's drawings in the 
Arch. f. Mik. Anat.) 

it has the function of secretion. More than this, the amoeba does not 
take in substances indiscriminately ; some it rejects. 



CELL-REACTIONS. 21 

If the observations are continued, it will be noticed that changes 
occur in the nucleus of the cell. A series of alterations in its figure 
are noted, as shown in Fig. 5. Two nuclei are formed, and soon the 
body of the cell divides and two cells appear — the amoeba has repro- 
duced itself. This primitive cell has, therefore, the properties of irrita- 
bility, contractility, secretion and excretion (as will be seen in later 
studies), and reproduction ; moreover, it responds to stimuli, as seen on 
warming the stage. 

If the stage be cooled, the movements of the protoplasm are less- 
ened, and when foreign substances come in contact with the cell it fails 
to encompass them — its irritability and contractility are lessened. 

It is noted that some simple cells are attracted and stimulated by 
light ; others are repelled by it. 

If a mild induction (interrupted) current be passed through the water 
in which the amoeba is, 1 the movements of the cell are checked ; if a 
strong current be passed, the cell contracts sharply. If a galvanic (con- 
stant) current be passed, movement at first ceases, but pseudopodia are 
extruded toward the cathode and the cell crawls toward that pole. 

The cell responds to mechanical stimuli, such as violent shaking, by 
contraction. 2 

If substances such as ether or chloroform are added to the fluid, the 
irritability of the cell is so lessened that it does not respond to stimuli. 

If the supply of oxygen be cut off, or if carbon dioxid be admitted 
to the fluid, movement ceases and the cell remains contracted. 

These examples serve to illustrate that protoplasm responds to 
stimuli of physical and chemical nature, and that its functions may be 
altered by substances which are brought in contact with it. Upon these 
facts depends the practice of therapeutics. 

A living organism, it will be seen, has a certain degree of action 
and function. The general average of its action and function is spoken 
of as a condition of health. When, from any cause, the functions are 
raised or lowered from the general average, a condition of disease exists. 

Stimulation. — Certain agencies applied to the cell increase its ac- 
tivity ; this is called stimulation. The movements of the cell become 
more rapid, food-particles are taken in more rapidly and disappear more 
quickly ; irritability, contractility, and secretion are increased. The 
cell subdivides, or reproduces more quickly. Increase the stimulation, 
and the vital activity becomes fretful ; in some cases cell-division is 
incomplete — the nucleus divides, but not the cell-body. Increase the 
stimulation beyond this degree, and the wearied cell ceases its move- 
ments — refuses to respond ; is paralyzed by overwork. 

Sedation. — If the conditions be reversed ; if, instead of applying a 

1 O. Hertwig, The Cell. 2 Ibid. 



22 GENERAL PRINCIPLES. 

stimulus to the cell, an opposite influence be introduced, the phenomena 
are reversed. 

If the temperature be reduced, the movements of the cell become 
sluggish ; the body changes its form more slowly and less extensively — 
i. e., contractility is lessened ; particles taken into the cell remain appar- 
ently unchanged ; irritability, secretion, and excretion are lessened ; and, 
furthermore, reproduction does not occur nearly so rapidly — that is, the 
cell in contact with sedative influences has all of its activities lessened. 

There are two great classes of influences, then, which affect the vi- 
tality of cells : stimulation, which, if continued long enough, leads to 
death through overwork ; and sedation, which, if continued, paralyzes 
all of the energies of the cell — it is starved to death. 

Every cell has a range of resistance to these influences which tend 
to destroy it, which is fitly termed the resistance of vitality. Disease 
itself is some alteration in any one or more of these several cell-proper- 
ties, of irritability, contractility, growth, secretion, maintenance, or 
reproduction. If any one of these properties is not exhibited, it is 
said that the cell is diseased. 

If a brood of cells derived from one parent be examined, some 
will be seen to grow more rapidly than others, their movements are 
more rapid and they reproduce more quickly ; others have sluggish 
functions and movements. 

The cell lives its cycle and reproduces, and the parent is no more, 
the life being continued in the offspring. 

The life and properties of this small mass of protoplasm represent 
in miniature the primitive functions and life of the highest animals. 

The contractility is represented in the motive apparatus of the higher 
animals. 

The reception, engulfing, and dissolving, or casting out, bodies with 
which the amoeba is brought in contact correspond in the higher animals 
with the digestive apparatus and process and the excretory function. 

The highly evolved irritability is represented in the nervous system 
of the higher animals. 

The movements occurring in and about the vacuole are the progenitors 
of the circulatory apparatus and all of its adjunct organs. 

If the irritability of a simple cell be increased or diminished, it 
corresponds with a disease of the nervous system, and so with the other 
functions. 

It is essential to the life of a cell that the means be afforded it of 
continuing the activities called life. First, it must receive a proper 
food-supply, which includes an abundance of water and such solid sub- 
stances, either contained in the water or dissolved in it, as are necessary 
to replace loss of substance in the cell ; these are albuminous substances, 



CELL-FUNCTIONS. 23 

to replace used-up nitrogenous matters ; carbohydrates and hydrocarbons, 
to replace the everchanging proportions of carbon and hydrogen of living 
matter ; and, lastly, the supply of oxygen must be sufficient. The cell 
must be maintained at a proper temperature. Its waste-products must 
be removed. If any of these conditions be interfered with, vitality is 
depressed. The most certain cause of prompt death is an absence of 
oxygen. Cell-life is maintained largely by a process of oxidation. 

In the performance of any vital act chemical change is inevitable ; 
that is, some portion or amount of protoplasm undergoes chemical 
alteration ; the substances brought as food by the circulating fluid are 
built into cell-substance to replace those which are lost ; the setting free 
of chemical energy by the process of protoplasm breaking down into 
simpler bodies is manifested in the production of heat. 

The oxygen about the cell combines with the products of cell- 
activity, and changes them into substances from which the cell frees 
itself — the waste, the products of its activity, is removed. The products 
of cell-activity are largely acid in reaction, and the increase of acid in 
protoplasm lessens its affinity for oxygen ; hence in an overworked cell 
oxidation is sluggish, for the outer portions of the cell have a lessened 
alkalinity. 

It is important that a familiarity with cell-properties be obtained, 
because the functions of any body are made up of the functions of its 
cells. As before stated, in the more highly evolved animals special col- 
lections of cells and special areas are set aside to perform the functions 
in which the entire substance of an amoeba participates. 

Certain collections of cells are found in which one function is active, 
the others in abeyance ; thus, large colonies of cells exist in which 
contractility is the dominant property noted ; these are muscle-cells. 
Others have but the property of irritability ; these are nerve-cells. 
Still others develop peculiar chemical functions, and become glandular 
or secretory cells. Such collections of cells are known as tissues. These 
special cell-colonies or tissues are built together into defined masses for 
the performance of their specialized functions. In the development of 
these masses, means of holding and maintaining the cells in definite 
mass-forms and provisions for their food-supply and waste-removing 
apparatus are provided in what are called the connective tissues, binding 
the cells in definite forms and transmitting their vascular supply (food- 
and waste-carrier). When thus bound together the tissues are said to 
form organs. 

In studying disorders which may affect any one or more organs, or 
their parts, the problem becomes apparently complex, but it ultimately 
resolves itself into a study of the disorders of the cells of the part. A 
disease may only be evident through disorder of some function, for 



24 GENERAL PRINCIPLES. 

when the tissue affected is studied no evidence of disease is seen even 
under the highest powers of the microscope. 

Another class of diseases will exhibit changes which have occurred 
in the anatomy of the part, which prompts the classification of diseases 
into functional and structural. Functional diseases are those which 
exhibit no demonstrable alteration in the anatomy of a part. Struc- 
tural diseases are those in which the anatomical structure of a part is 
altered. 

Definite anatomical changes have been found constantly associated 
with a more or less constant group of symptoms. The changes are 
spoken of as the morbid anatomy of a disease. 

The pathology of any disease means the morbid physiology through 
which these anatomical changes are brought about. In the absence of 
direct anatomical examination of any organ a knowledge that it is not 
performing its work properly and that its functions are disordered is 
obtained by noting whatever phenomena are obtainable. These are, in 
part, what the observer may note through the use of his senses, and by 
utilizing the resources of physics and chemistry. Knowledge gained by 
such means is called the objective evidence of disease. Certain facts 
are elicited by questioning a patient as to altered sensations, the nature 
and situations of pain, etc. ; these are known as the subjective evidences 
of disease. 

The study of symptoms elicited from the patient by examination and 
noted in his physical appearance is known as Semeiology, from semeion, 
a mark or sign. 

A special study is made of the influences and conditions through 
which the functions of the body are disordered ; this is known as Eti- 
ology. 

It is noted that diseases presenting a certain or an uncertain morbid 
anatomy and a constant course of symptoms have from their beginning 
to ending tolerably constant phenomena ; they have each a natural his- 
tory ; this is called the Clinical History of a Disease. 

There are symptoms which are common to many disease-conditions, 
and others which are associated with but some one distinctive morbid 
state ; different diseases may exhibit several symptoms in common, and 
some few, which serve to distinguish the one from the other. The study 
which deals with that discrimination between groups of symptoms 
which characterize distinct diseases is called Diagnosis, from Greek dia, 
through, and gignosko, I know. It embraces a consideration of all of 
those phenomena which indicate the exact disease-state present. 

In the study of the clinical history of diseases it is observed that 
while each disease has a more or less well-defined natural history, they 
vary as to the course followed in individuals and the final outcome. It 



STUDY OF DISEASE. 25 

is observed that there are signs and symptoms which are followed by 
good or ill results, as the case may be. By these signs and symptoms 
it may be foretold with some degree of assurance what will be the prob- 
able outcome of the disease. The branch of inquiry dealing with this 
aspect of disease-study is known as Prognosis, from pro, before, and 
gif/nosko. 

It is found that agencies described in the succeeding chapter as dis- 
ease causes affect tissues and organs in such manner that their phys- 
iology is altered and changes occur in their anatomical structure. The 
occurrence of these disordered functions and structures is attended by 
signs and symptoms which indicate their presence. The study of these 
particular features of disease is called Pathogenesis ; while it might be 
inferred from the etymology of this word {pathos, disease, and gennao, 
I produce) that it was but another name for etiology, it covers a wider 
field. 

Recognizing by the presence of signs and symptoms that the phys- 
iology of one or more organs is disordered, and that probably changes 
of structure have occurred, the great problem of the healing art is to 
apply such measures and agencies as shall restore the tissues or organs 
to their normal condition and function. This branch of medicine is 
known as Therapeutics, from therapeuein, to take care of, to heal. 

Centuries of observation have shown that there are numerous 
agencies and substances which are capable of producing alterations in 
the action or physiology of organs ; these agencies and substances are 
included in what is called the Materia Medica — the materials of 
medicine. 

An increasing importance attaches to that method of studying the 
feature of the healing art which begins with a knowledge of the exact 
chemical composition of each substance used, and traces with the utmost 
care the effects of these substances upon the chemical composition and 
the functions of organs, and how these effects may be utilized in com- 
bating disease ; this study is called Pharmacology. 

The method of treating disease which begins with an exact knowl- 
edge of the causes of diseases, the significance of their symptoms, and 
their clinical history, together Avith the nature of the alterations of the 
physiology of organs which give rise to symptoms, and the reasons and 
nature of the anatomical changes which result from this altered phys- 
iology, and embracing an exact knowledge of the effects of agents in 
the materia medica, which properties are to be utilized in such manner 
that the causes, phenomena, and results of disease are neutralized, is 
called Rational Therapeutics. 

Such precise familiarity with the nature of disease, and, upon the 
other hand, of the action of therapeutic agents, is not a possession of 



26 GENERAL PRINCIPLES. 

medicine ; although it had been noted and confirmed by years of obser- 
vation that the application or administration of certain agents is 
followed by a disappearance of symptoms and of the evidences of 
disease ; the type of treatment pursued upon this basis is called 
Empirical Therapeutics. 

When it is observed that patients exhibit groups of symptoms 
which appear as constant features of clinical histories, which are alike, 
and it is further noted that the causes giving rise to these symptoms 
are identical, and when, furthermore, examination shows the same 
organs to be affected in one manner, a distinctive name is applied 
to describe the condition ; it is known, or designated, as some distinct 
disease. For example, a number of persons who drink water from a 
common source are, one by one, affected by diarrhoea and a gradually 
rising temperature of the body, followed by evidences of debility and 
general poisoning, which symptoms subside after about three weeks : 
the patients are said to have the distinctive disease, typhoid fever. 

It is preferable, when it can be done, to name a disease to accord 
with its anatomical and physiological features. For example, chem- 
ical examination of a patient's urine shows it to contain albumin ; ex- 
amined under a microscope it shows what are called tube-casts ; at a later 
period, dropsy or cedemas (which see) appear, and the patient exhibits 
evidences of poisoning, and later dies. On examining the tissues of 
the body it is found that the secretory or parenchymatous portions of 
the kidney are destroyed ; the disease is designated then as parenchy- 
matous nephritis. This word is derived from parenchuma, the sub- 
stance of organs, and nephros, a kidney, the termination itis signifying 
inflammation. This suffix always means inflammation ; for example, 
inflammation of a joint is known as arthritis, from arthron, a joint ; 
pulpitis, inflammation of a tooth-pulp, and so on. 

Some disorders can only be named from a symptom, as neuralgia, 
from neuron, a nerve, and algos, pain. The suffix algos always signi- 
fies pain in the organ or tissue named in the stem of the word, as 
odontalgia, stem odont, from the Greek oclous, a tooth. 

Pains of a rheumatic character are described by the suffix dynia, 
from odime, pain, as in pleurodynia, from pleura, the side, and odune, 
pain. 

Pains of gouty origin are named by the suffix agra, a seizure, as 
podagra, from pous, poda, a foot, and agra, a seizure, which describes 
gout of the foot. Odontagra would be the name applied to gouty pain 
in or about a tooth. 

Before the diseases or disorders of any tissue or organ can be 
studied intelligently it is necessary that the student be familiar with 
the anatomy of the part, as revealed by the scalpel, or macroscopic 



STUDY OF DISEASE. 27 

anatomy, and as revealed by the microscope, the histology of the organ 
and the tissues of which it is composed, or its microscopic anatomy. 
It is necessary that a knowledge of its physiology be acquired; the 
nature of the work performed, how and by Avhat performed. The nature 
of the chemical changes which occur in tissues and organs should also 
be known ; and, finally, the mode of development, the embryology of 
the tissues and organs, should be studied. 

It is customary - in fact, almost necessary — that a disease be studied 
systematically in all of its bearings. First, What is the definition of 
the disease ? Secondly, How has it been studied in the past ? — i. e., What 
is its history ? A study of etiology, or the causes of the disease, follows. 
Next, What is its semeiology ? — i. e., What are its symptoms ? Next an 
inquiry is directed to the nature of the alterations in the physiology of 
the parts involved, and what changes of structure occur — i. e., a study of 
the pathology and morbid anatomy of the disease. The clinical history 
is next taken up, and followed by a consideration of its diagnosis ; its 
prognosis or probable outcome is next adjudged ; and, finally, the ques- 
tions of How shall the disease be combated? What shall be its 
treatment? 

With an increasing knowledge of the pathogenesis of diseases, it is 
but natural that it should lead to the study of the rational methods of 
preventing disease — i. e., their prophylaxis (Greek pro, before ; phulasso, 
I preserve ; and phulax, a guard). It is manifestly preferable to prevent 
disease than to permit its onset and treat the condition. Before intelli- 
gent efforts can be directed toward the prevention of disease a knowl- 
edge of disease-causes is necessary, for the prophylaxis of any disease 
is the destruction or neutralizing of its causes before they have oppor- 
tunity to act. 



CHAPTEE II. 

CAUSES OF DISEASE, GENERAL AND LOCAL. 

A disease-cause may be defined as any influence of whatsoever 
nature which is capable of disturbing the nutritive balance of any por- 
tion of the body. That branch of study which deals with the causes of 
disease is called Etiology, from Greek actios, causes, and logos. 

Every living organism and all parts of the more highly organized 
animals possess the power of maintaining a nutritive balance despite 
changes in their surroundings ; moreover, they persist as living bodies 
though assailed by forces which tend to disturb the complexus of phe- 
nomena called life, even though these forces do frequently bring about 
modifications in their capacity for work. All of these threatening influ- 
ences may be regarded as disease-causes, and an examination of the 
forces which tend to disturb the natural working of portions of the body 
will show them to be very numerous ; but, as will be seen later, they 
may be grouped under a few convenient headings. 

This study deals with the forces and influences which act upon the 
body from the outside ; they are called the extrinsic causes of disease. 

The evolutionist points out that all animals of a species are not 
equally resistant to the same causes acting upon all, for if a number of 
animals be placed under identical conditions, some will be more strongly 
affected than others ; some are, therefore, said to have a greater inherent 
resistance than others. The reason for this difference in resistive power 
is spoken of as intrinsic ; the causes of the lessened resistance, as the 
intrinsic causes of disease. The cause of the condition may be sought 
for in all three of the factors which go to make up the analysis of cell- 
life, chemical, physiological, and anatomical ; although it is at times 
difficult or even impossible to determine exactly which element is at 
fault. An examination of the part may reveal some structural change, 
some alteration of its anatomical forms ; or, again, it can only be said 
that the part does not functionate properly, or it may be that the evi- 
dence of disorder is a persistent deficiency in the chemical nature of 
cell-products. It is impossible to separate the physiological from the 
chemical side of this problem. 

The only present, tangible conditions which can be regarded as purely 
intrinsic disease-causes are changes in anatomical structure. Changes 
or conditions which alter the physiological action of any part of the 

28 



PREDISPOSING CA USES OF DISEASE. 29 

body, so that it succumbs to influences which normally it should resist, 
are called predisposing causes of disease. It is evident that what are 
termed intrinsic causes are all predispositions. It is customary, there- 
fore, to divide the study of disease-causes under two heads : first, all 
of those conditions which render any part more susceptible to the ac- 
tion of inimical forces, or the predisposing causes of disease ; secondly, 
those to whose action upon the body disease is directly due, or the ex- 
citing causes of disease. A predisposing cause may be intrinsic or ex- 
trinsic, which is also true of the exciting causes, so that we may divide 
both the predisposing and the exciting causes into intrinsic and extrinsic. 

Predisposing Causes of Disease. 

Life in itself is a persistence of energy in a chemical substance 
of unknown nature, against forces which tend to disturb its chemical 
integrity, and, as a consequence, its energy or its structure. Any 
forces or influences acting from within or without an organized mass 
of the substance, which lessen its resistance to those forces, predispose to 
its destruction. Applied on a large scale, there comes the study of 
the influences which tend to lessen the resistive forces of the body. 
The first of these is naturally an alteration of anatomical structure, for 
if there is a standard of structure best adapted to meeting and over- 
coming conditions to which living bodies are subjected, any variation in 
this standard is necessarily followed by lessened resistance. 

These alterations of structure may be congenital or acquired ; they 
may be due to a faulty development which may be traced to the ovum 
or the spermatozoa of the parent, or they may arise after birth and a 
period of apparently normal development. The abnormalities may be 
macroscopic, so evident that they are seen at a glance to be malforma- 
tions ; or they may be microscopic, requiring special preparation of por- 
tions of organs to demonstrate their existence. 

Sex as an Intrinsic Predisposing" Cause. — In this connection the 
influence of sex upon predisposition to disease must be considered. 
While the general resistive power of the bodies of both sexes may be 
regarded as practically equal under similar conditions, yet the anatom- 
ical structures and physiology of each sex have an influence upon predis- 
position to certain diseases. Aside from the diseases peculiar to sex, 
on account of their peculiar organs, each sex exhibits predisposi- 
tions to diseases which the other sex escapes ; for many of these the 
habits of life furnish an explanation, for others an explanation is not 
available. For example, while women are predisposed to functional 
and emotional disturbances of the nervous system, such as hysteria, they 
are almost exempt from such structural nervous diseases as locomotor 
ataxia and general sclerosis. 



30 CAUSES OF DISEASE, GENERAL AND LOCAL. 

Men may become anaemic from a variety of causes ; but young girls 
become chlorotic, a disease- type which rarely affects the male. 

Women are affected by diseases of internal secretory glands, as the 
thyroid, and escape affections of others, as of the suprarenal capsules. 

Age as an Intrinsic Predisposing- Cause. — The cycle of life of an 
organized being comprises an intra- and an extra-uterine development 
until maturity is attained ; while increment exceeds excrement, growth 
is in progress. This is followed by a period in which increment and 
excrement are balanced ; Avaste and repair are equal ; this is the period 
of maintenance. Succeeding is the period of decadence, when the 
tissues of the body undergo gradual changes leading to exhaustion ; the 
vital forces are lessened ; the power of repair does not equal the waste 
occurring throughout the body. In each of these periods there is 
exhibited a predisposition to certain diseases. 

Intra-uterine causes acting produce abnormalities of structure — a 
general intrinsic predisposition. During the first period of extra- 
uterine growth there is a predisposition to gastro-intestinal disorders 
and reflex disturbances of the nervous system. At a later period there 
is a predisposition exhibited to the eruptive fevers, scarlatina, rubeola, 
varicella, and variola, and also to diphtheria — diseases which are 
called the diseases of childhood. Later, in the period of adolescence, 
other predispositions occur in young girls, notably chlorosis. Later 
come the diseases of early maturity, such as typhoid fever. Diseases 
characterized by degenerative changes in the tissues and organs are so 
distinctive accompaniments of senility that they are called the diseases 
of old age. 

Temperament as an Intrinsic Predisposing Cause. — The influence 
of temperament upon disease is frequently overlooked. Accepting as a 
basis the classification of Hippocrates as indicating the four classes of 
temperament, it may be said that persons of the sanguine tempera- 
ment have a predisposition to acute pulmonary and cardiac diseases, 
together with those of the bloodvessels ; inflammatory disorders are 
disposed to run a riotous course. Those of the nervous temperament, 
to disorders of the corresponding anatomical system, particularly func- 
tional disorders. Those of the bilious temperament exhibit a predis- 
position to affections of the liver. Those of the lymphatic temperament 
have a predisposition to passive congestions. The truth of these rules 
may be more apparent than real, for close scientific studies relative to the 
subject of temperament are extremely meagre. 

Heredity. — Certain diseases exhibit a predisposition to descend from 
parent to child ; as, for example, gout, rheumatism, syphilis, the tuber- 
cular diathesis, epilepsy, etc. The mode of transmission is in all prob- 
ability the inheritance of a type of tissue ; a tissue anatomy and phys- 



IMMUNITY. 31 

iology which permit the more ready action of the exciting causes of 
these maladies. These cases might perhaps be fitly included under the 
head of malformations, though the malformations may be undiscover- 
able. Persons who exhibit this tendency to an hereditary disease such as 
gout are said to have that diathesis. The hereditary victims of such 
diseases as syphilis are said to be cachectic. 

Existing- Disease. — The presence of one disease may predispose to 
others, as, for example, acute rheumatism predisposes to organic dis- 
ease of the heart-valves ; however, in this as in many diseases, what 
appear to be supplementary diseases may be but phases of the same 
disease. 

Previous Disease. — Frequently a part which has once been the seat 
of disease is, when apparently recovered, the seat of the same disease 
or other disease at a subsequent period. Previous disease may, on 
the contrary, confer immunity from the same disease in the future. 
This principle is of wide and increasing application in medicine. 
Notable examples of this are found in smallpox (variola) and in scarlet 
fever (scarlatina), and to a less extent in typhoid fever. 

Extrinsic Predisposing" Causes of Disease. — Under this head are 
included all of those conditions which cause a person to fall a victim 
to a disease when exposed to its active causes. Cold and damp are 
among the conditions which act as predisposing causes of disease, as, for 
example, to pneumonia, rheumatism, and a number of inflammatory 
disorders. Dentists note how cold and damp act as predisposing influ- 
ences in the induction of pericementitis. The reasons for this will 
appear in the discussion of hyperemia. 

Immunity. — When a number of persons are exposed to the active 
causes of disease it will be seen that some succumb to the disease 
immediately ; others are unaffected — L e., they are immune. Some are 
not affected no matter how prolonged the exposure ; others exhibit a 
tardy response to the action of the disease-cause. The reasons for 
these degrees of natural insusceptibility are but imperfectly understood. 

Immunity from a particular disease may be inherited or acquired. 
It may be exhibited toward only one disease. In some, disease ap- 
pear to be influenced by sex — as, for example, males have a general 
immunity from goitre ; females, immunity from Addison's disease. 
Immunity is influenced by age in certain diseases ; for example, the 
diseases of childhood are rare in the elderly ; they do occur, however. 
The degenerative diseases of old age are almost unknown in childhood. 
Race has its influence ; the negro is peculiarly susceptible to smallpox, 
and almost immune from malaria. 

Natural immunity is a very uncertain quantity ; there is no method 
of determining its duration without direct exposure. 



32 CAUSES OF DISEASE, GENERAL AND LOCAL. 

The most interesting and useful feature of immunity is the possi- 
bility of its acquirement through natural, or its induction through 
artificial means. It had been noted, as long ago as certain conditions 
were recognized as definite diseases, that those who recovered from 
them were rarely the subjects of the same disease in the future, although 
exposed to actively contagious influences. The classical example of 
this acquired immunity is smallpox. We are indebted to Saracen 
medicine, adopted or followed by the Turks of Constantinople, for the 
early studies as to artificial immunity from this disease. Noting, no 
doubt, that virulent contagion was associated with the pustular stage 
of. smallpox ; that immunity of some persons did exist ; and that the 
disease Avas self-protective : a minute portion of the virus was intro- 
duced into the bodies of healthy persons. This induced in most of 
them the disease in a milder form, and, although the death-rate was con- 
siderable, an acquired immunity was the result. In 1718 Lady Mary 
"Wortley Montague introduced the practice into England, where it met 
with much opposition and limited adoption. It may be remarked that 
the mortality of the cases inoculated is but from 3 to 5 per 1000. In 
1798, Jenner, an English physician, applied the rustic knowledge that 
persons who had been inoculated with the virus of cowpox were insus- 
ceptible to smallpox, and became the virtual founder of inoculation by 
attenuated virus. This practice in its later phases is one of the most 
important developments of modern medicine. 

The exact method through which inoculation brings about immunity 
can at present only be surmised. (See Bacteria (alexins).) It is impor- 
tant to remember, as illustrated in the principle of vaccination, that 
living bodies have protective mechanisms against disease which undergo 
variations in degree of activity, and that this activity is in some cases 
susceptible of artificial alteration. 

Exciting Causes of Disease. 

Under the head of the exciting causes of disease are included all of 
those variations in bodily and cellular environment which interfere 
with the normal performance of function. The conditions of cellular 
life are, that cells must receive a proper food-supply, must have removed 
the waste-products resulting from their life-processes, and must be main- 
tained at a proper temperature. In a complex organ the process of 
nutrition is more complicated, and a greater number of elements must 
be studied, for not only are the food-supply and waste-removal relegated 
to special structures, but a nervous element is introduced. 

All of those causes which relate to food-supply, all of the processes 
which food undergoes while being changed into substances fit for cell- 
nutrition, the removal of waste, and also the supply of oxygen, may be 



EXCITING CAUSES OF DISEASE. 33 

grouped under the head of abnormal blood-supply. In studying the 
influences which are grouped under this head, every stage through 
which the food passes in being changed from albumins, fats, and 
starches, into material to be utilized by cells, the composition of the 
blood, its mode of distribution, its supply of oxygen, the removal of 
waste-substance from cells and its elimination from the body, must 
be taken into consideration. 

Abnormal Food-supply. — When a man has attained maturity 
waste equals repair in the body ; sufficient food is taken into the body, 
carried to the organs and utilized by their cells to replace the sub- 
stance lost through functional activity, the waste-substances being oxi- 
dized by the oxygen carried by the red blood-corpuscles ; carbon clioxid, 
urea, and other waste-substances are formed, which are immediately re- 
moved from about the cells. Each cell is a chemical laboratory in min- 
iature, and any variation in the nature of the substances present pro- 
duces changes in the chemical interchanges or reactions. 

It is evident, therefore, that the study of abnormal food-supply is an 
extensive one, for the cause of the presence of improper pabulum may 
be traced to any stage of nutrition from the non-reception of the proper 
amount and quality of food and its imperfect mastication, to faults con- 
nected with glandular secretion of the alimentary tract, to faulty opera- 
tions while the digested and absorbed food-stuffs are in the portal system ; 
next, to the general character and condition of the circulatory system, 
to the time when the pabulum is in the lymph-spaces. Any abnor- 
mality of function in any one of these particulars may be followed by 
imperfect nutrition of cells. 

"Waste -products as Disease-causes. — For the normal performance 
of cell-function it is quite as essential that cells should have their waste- 
products removed as it is that they should receive a sufficient supply 
of pabulum and oxygen. 

Waste-products of cell-action are the ashes of the vital fire ; are oxi- 
dized products of cell-contents which have a simpler chemical composi- 
tion than the pabulum or cell-materials out of which they are formed. 
Principal among these products are carbon dioxid and the product of 
albuminous waste — urea. Numerous other substances are formed, such as 
xanthin, uric acid, etc. If when these substances are formed, they are 
not removed, they act as ashes in the vital furnace, clog the fuel, and 
lessen oxidation. Retained, they inevitably interfere with the nutrition 
and function of cells, and disease results. If taken into the blood and 
through faulty action of the great eliminant organs — the kidneys and 
lungs — they are not removed, they act as disturbing elements through- 
out the body ; for example, should the functions of the kidney be de- 
stroyed through disease, urea is not eliminated, and, remaining in the 
3 



34 CAUSES OF DISEASE, GENERAL AND LOCAL. 

circulating fluids, causes symptoms of poisoning — uraemia. Uric acid 
is normally formed in small amounts • if formed in increased amount 
and not eliminated, owing to disease of the kidneys, it gives rise to a 
long chain of symptoms, characteristic among which are those com- 
prised under the head of the several forms of gout. It is extremely 
probable that many diseases of obscure nature may be due to the reten- 
tion and circulation of waste-products. 

The Presence of Poisons. — The presence of introduced poisons 
in the body, such as mineral and vegetable poisons, must be regarded 
as disease-causes : for what are termed the symptoms of poisoning by 
toxic drugs are alterations of cell-nutrition, and hence are diseases ; 
short and violent ones in many instances, prolonged in others ; for exam- 
ple, the chronic poisoning by ergot (see works on materia medica). 

Of late years a new group of poisons has been discovered, which 
shows that toxication is widespread and common. 

Organic poisons are formed by the action of bacteria (see next chap- 
ter) during the process of digestion, are absorbed, and give rise to toxic 
symptoms. Owing to the presence of specific bacteria, poisons are gen- 
erated in the body, which, finding their way into the circulatory fluids, 
give rise to symptoms of poisoning. 

The Influence of Anaemia. — The presence of oxidizable material 
and the removal of the oxidized material having been discussed, there 
remains another important factor — the oxidizer itself. Oxygen is 
received by the red blood-corpuscles in the capillaries of the lungs ; it 
combines with the hemoglobin, an albuminate of iron, forming oxy- 
hemoglobin, which in the capillaries throughout the body gives up its 
loosely combined oxygen to the tissues, is reduced, and takes up carbon 
dioxid, an excretory product. It is evident, therefore, that the volume 
of oxygen distributed throughout the body depends upon the amount 
of hemoglobin present — i. e., upon the number of red corpuscles in the 
blood. A deficiency in this direction means lessened oxidation and its 
attendant effects. 

Condition of the Circulatory System. — If, as a consequence of 
faulty action on the part of the heart or changes in the structure of 
the bloodvessels, the blood is not normally distributed, there is a result- 
ant influence upon the distribution of nutritive material, and nutrition 
is disordered ; for example, if as a consequence of disease of any of 
the heart-orifices the pressure of the blood in the vessels is lessened, 
changes in the nutritive balance result. If as a result of changes in 
the walls of vessels their elasticity is lessened, it is followed by faulty 
distribution of the food-supply. If any mechanical interference exist 
to the return-flow of the blood, stagnation with a retention of waste- 
products must follow. 



EXCITING CAUSES OF DISEASE. 35 

The disease-causes thus far discussed have relation to effects upon 
the chemistry of tissue-life ; there remain other classes of disease-causes 
of great frequency. The first comprise all of those physical conditions 
or forces which act upon vital tissues and depress their activity or 
actually destroy them. They may be classed under the head of abnor- 
mal physical conditions. 1 

Abnormal Physical Conditions. — This class of disease-causes in- 
cludes all injuries due to any of the physical forces. All surgical 
injuries may be placed under this head — diseases due to trauma. There 
are also included in the group diseases arising as a consequence of 
obstruction to ducts and to the natural outlets of the body. The actual 
causes of disease in these cases are secondary effects upon nutrition, 
arising out of faulty nutrition, and very frequently in consequence of 
retained waste-products. 

Among the intrinsic causes of disease should be mentioned the influ- 
ence of the nervous system. It is believed by some physiologists that 
there are special nerve-fibres whose function it is to preside over the 
nutrition of the parts of the body to which they are distributed ; these 
have been called trophic nerves. Unfortunately, the data upon which 
this belief is founded are too involved and too few to base positive 
opinions upon. It has been noted that when the Gasserian ganglion, 
the ganglionic centre of the great sensory nerve of the face, has been 
destroyed ulceration of the cornea has resulted, which has been attrib- 
uted to the destruction of trophic nerves ; but when the eyeball is pro- 
tected by stitching together the eyelids, so that there is no admission of 
foreign matters, ulceration does not occur. The more rational explana- 
tion, therefore, is that the ulceration is due to the loss of sensibility, 
the cornea not being able to recognize the presence of the foreign body. 
Again, injuries to nerves are followed by affections of parts to which 
the nerves are distributed. The classical example of this is that of 
Charcot; the occurrence of acute bedsores in cases of certain degen- 
erations of some portion of the central nervous system, which cause 
paralysis. Hyperemia, inflammation, and necrosis occur in rapid 
sequence over the hip or over the sacral region. The evidence is, how- 
ever, insufficient to prove the presence of special trophic fibres. Many 
or most of the effects are perhaps more rationally explained by the 
theory of vasomotor influence upon nutrition. The calibre of the 
vessels is governed by special fibres, which by causing degrees of dila- 
tation of the walls of vessels cause modifications of nutrition (see chapter 
on Vascular Disturbances). 

Diseases are usually classified as general or local : the first class are 
those in which evidences of disturbance exist throughout the body at 

1 Green's Pathology and Morbid Anatomy, 8th ed. 



36 CAUSES OF DISEASE, GENERAL AND LOCAL. 

large ; the second, those in which the disease-manifestations are confined 
to some special region of the body. While this classification is useful 
in describing or naming distinguishing features between diseases, it is 
faulty in that it fails to describe the actual conditions existing. Some 
local diseases are manifestations of a general disease-process becoming 
evident in some one area ; and, again, some general diseases are due 
primarily to disease which may be definitely localized in one region of 
the body. For example, in observing a typical case of gout it might 
be thought that the disease of the great toe was a local malady, when it 
is but the expression of a general cause acting locally ; or, again, in 
observing the symptoms of typhoid fever it might be believed that the 
disease was a general one, which in one sense it is, but the primary 
cause is found in a bacterial ulceration of Peyer's patches in the small 
intestine, the constitutional symptoms being caused by the absorption 
and circulation of the poisons generated by the bacteria. Year by year 
the number of diseases traceable to a local source becomes greater, and 
the number classed as constitutional grows less. 



CHAPTER III. 

BACTERIOLOGY, WITH SPECIAL REFERENCE TO DENTAL 
PATHOLOGY AND THERAPEUTICS. 

Within the past twenty years a virtually new study has been intro- 
duced into medicine and surgery and their dependents, namely, that of 
Bacteriology. It is not to be understood that previous to this time 
what will be in the following pages studied as bacteria were unknown, 
but that it is only within that period that such modes of studying these 
organisms have been devised as render the study of direct practical use. 

In 1683 x Leeuwenhoek described bacterial forms obtained from 
scrapings of the human teeth. As early as 1762 Plenciz, 2 of Vienna, 
advanced the opinion that the bacterial forms, or animalcules as they 
were called, described by Leeuwenhoek and observed by himself, 
were the cause of all infectious diseases. These opinions did not re- 
ceive general endorsement, and although the study of micro-organisms 
was pursued, it was not until some eighty years after that the germ- 
theory of disease received serious attention, when Henle taught the 
modus operandi of the bacterial origin of disease. 3 

The invaluable and immortal studies of Louis Pasteur demonstrated 
the physiology and physiological chemistry of bacteria, and showed con- 
clusively the nature of fermentative processes. 

Koch, through the devising of methods of isolating varieties of 
micro-organisms based upon their elaborately worked-out physiologv, 
was the first to demonstrate clearly the relations between bacteria and 
infective diseases. Louis Pasteur had, however, previously studied and 
pointed out the relationship between plant and animal infectious diseases 
and bacteria, and had shown the modes of effectually combating such 
diseases. 

Sir Joseph Lister's name has been so closely associated with that 
mode of surgical operating which deals with the freeing of wounds from 
bacteria, that modern antiseptic surgery is known as Listerism. 

In order that bacteria as disease-causes may be studied systematically, 
the position of bacteria in the life-scale and their physiology must be 
examined into. It is noted, first, that their properties show them to 
belong to the vegetable kingdom, they occupying the lowest step of the 

1 Abbott's Bacteriology. 2 Ibid. 3 Ibid. 

3? 



38 BACTERIOLOGY. 

kingdom. All plants l are divided into two great classes, Phanerogamia 
and Cryptogamia. Phanerogams are those which flower and reproduce 
by seeds. Cryptogams are destitute of flowers, and reproduce through 
the medium of spores. Cryptogams are divided into two groups, those 
in which there is no distinction between leaf and stem, Thallophytes 
(Greek ihallos, a young shoot, and pliuton, & plant), and those which 
bear leaves, as many water plants. 

The Thallophytes are subdivided into algse, lichens, and fungi. 
The last-named order is that with which bacteria are classed. Fungi 
contain no chlorophyll, and hence are unable to derive their nutriment 
from inorganic material. Chlorophyll, the green coloring-matter of 
plants (chloros, green, and phullon, a leaf), is the substance through the 
agency of which carbon dioxid, C0 2 , and ammonia, NH 3 , are broken 
up and built anew into substances tit for the nutrition of plants. It is 
the substance which effects the decomposition of water and carbon 
dioxid and their recomposition into starch: 

6C0 2 + 5H 2 = C 6 H 10 O 5 + 12 . 

Fungi are, therefore, compelled to derive their nutritive material from 
existing organic compounds, which is, in fact, the reason why they 
become disease-causes. They are subdivided into four groups: 2 1. 
Fission-fungi — Schizomycetes ; 2. Mould or thread-fungi — Hypho- 
mycetes ; 3. Bud-fungi — Yeasts, Blastomycetes ; 4. Animal fungi — 
Mycetozoa. All of these groups are interesting as throwing light upon 
many of the problems of pathology, and it is quite essential to compre- 
hend the second class named in order to render clear the physiology of 
the first group, which is one of immediate and special interest to the 
pathologist. 

Bacteria are vegetable organisms of extreme minuteness, many of 
them requiring high-power objectives and special staining-methods to 
make them visible. Owing to their methods of division they are 
termed fission-fungi, or the equivalent, schizomycetes, from Greek schizo, 
to split or rend, and mukes, a fungus. Like many other cells, they possess 
a cell -body and a cell-wall, and some of them a nucleus ; their substance 
and cell- wall are composed of a modified protoplasm, called mycoprotein ; 
the cell-wall of some is composed of cellulose. Some of them possess 
flagella, by which movement is effected. They are devoid of chlorophyll, 
and are thus unable to decompose carbon dioxid and water, and to effect 
the synthesis of starch from the elements of those compounds. To 
secure the carbon necessary to their life-processes they require to be 
brought in contact with solutions of carbohydrates. Their nitrogen is 

1 Thome, Structural and Physiological Botany. 

2 Miller, 3ficro-organisms of the Mouth. 



VARIETIES OF BACTERIA. 39 

derived from albuminous substances with which they come in contact. 
Although these are the usual sources of the substances required for the 
life of bacteria, solutions of chemical substances may be made in which 
the growth of the organisms proceeds. The conditions necessary to their 
life and multiplication are, in general, the same as for all living bodies ; 
they must have a proper food-supply, must be maintained at a suitable 
temperature, must be born or generated with normal vitality, and must 
have waste-products removed from in and about them. These factors 
vary within wide limits, as will be seen later. Their classification is 
attended with much difficulty ; at present a classification based upon the 
form of the organisms appears to be as satisfactory as any. They are 
divided into three great groups — 

1. The micrococci (rnikros, and kokkos, a berry), including all of the 
spherical forms, or those having equal or nearly equal diameters. 



Fig. 6. 



oo 

o9 



QC °QOOO 

b 



%co CD 



« * 




Oo go <JP 

c d e 

a, staphylococci ; b, streptococci; c, diplococci; d, tetrads ; e, sarcinse. (Abbott.) 

2. The bacilli (bacittum, a rod), or rod-like forms ; one diameter 
being greater than the other. 

3. The spirillar (Greek spira, a coil), or the curved forms. 

All of these groups may be again subdivided. The micrococci are 
subdivided according to their modes of grouping. Double cocci are 
called diplococci (diploos, double). If in division the cocci arrange 
themselves in a line, they are called streptococci (streptos, a chain). If 
they agglomerate in bunches, they are termed 
staphylococci (staphyle, a grape). The organ- ",''. 

isms, upon reproduction, form groups which are 
called zoogloea masses, the substance holding 
them together being formed by their cell-walls. 
The bacilli are of many and varied forms and 
differ as to their modes of grouping. They 
exhibit, in the same species, differences of form 
at different periods of their development. Many of them form spores 




40 BA CTERIOLOG Y. 

(see Fig. 8). When brought under conditions unfavorable to their 
vitality " individuals themselves undergo alterations in their outline 

Fig. 8. 

'.O Ur As Tr 

a b c d 

a, bacillus subtilis with spores ; b, bacillus anthracis with spores ; c, Clostridium with spores ; 
d, bacillus of tetanus with end-spore's. (Abbott.) 

with the appearance of so-called involution -forms " (Abbott). The 
bacilli may again assume their typical forms when brought under 
conditions favorable to their development. 



Fig. 9. 







a, spirillum of Asiatic cholera (comma bacillus) ; b, involution-forms of this organism as seen in 

old cultures. (Abbott.) 

Bacteria may be again divided, according to their mode of life, into 
the saprophytes (sapros, rotten, and phuton, a plant) and the parasites 
(para, near, and siteo, I nourish). 

The saprophytic fungi are those which derive their nutrition from 
and multiply upon dead organic matter ; they are the forms which break 
down dead animal matter from such complex molecules as albumin into 
the end-products — carbon dioxid, C0 2 , ammonia, NH 3 , and hydro- 
gen sulfid, H 2 S. Succeeding varieties of this group form from albu- 
minous matters a series of substances having an increasing simplicity 
of composition. The saprophytic fungi play an important role in the 
economy of nature, as the products of the progressive decomposition 
cited serve as food for higher plants. 

Parasitic bacteria are those which develop in the tissues of living 
animals and produce disease ; they form the greater number of the 
group known as pathogenic organisms. All of the bacterial forms 
are to be found in this class. They gain access to the body through 
wounds, frequently large surgical wounds ; by surfaces deprived of epi- 
thelium ; a minute break in the continuity of the internal or external 
epithelial covering of the body may permit the entrance of the organ- 
isms to deeper tissues, where, under favorable conditions, they multiply 
and produce their specific effects. To generalize the effects of the 



FERMENT A TION. 41 

development of pathogenic organisms in the tissues : "At the point of 
multiplication, degenerations, necrosis, inflammations, and new growth 
of tissues, while the toxalbumins produced cause manifestations of 
poisoning. According to the variety of organisms, one or more of 
these results may predominate " (Ziegler). Many forms of organisms 
have points of election in which they find the most suitable soil for 
development, viz., the typhoid bacillus, in the glands of the ileum, 
Peyer's patches ; the diphtheria bacillus, in the mucous surfaces of 
the pharynx and contiguous parts. 

Many bacterial forms find a suitable habitat in the human mouth ; 
the conditions of their food-supply and temperature invite the habitation 
and development of forms of all three of the groups cocci, bacilli, and 
spirilla, together with the characteristic leptothrix. This subject will 
be discussed in detail later. 

In order to comprehend how bacteria act as pathogenic or disease- 
producing agents {pathos, disease, and gennao, I produce) an examina- 
tion must be made into their physiology and physiological chemistry. 

Fermentation. 

Fermentation may be defined as " the series of changes which 
occur in solutions of organic substances exposed to the air, which re- 
sult in radical changes in their chemical composition ; " as, for exam- 
ple, the change of a solution of sugar into alcohol and carbon dioxid, 
and later into acetic acid, the formation of lactic acid in milk, the 
putrefaction of albuminous substances, and so on. The opinion that 
these changes are due to a simple oxidation may be entirely set aside. 
Although these decompositions are due to oxidation, hydration, and 
reduction, it has been clearly demonstrated that it is through the agency 
of fungi, and not mere contact with the oxygen of the atmosphere. 

Sims Woodhead l comprehensively defines fermentation " as essen- 
tially the breaking up of chemical compounds, the molecules of which 
they are composed being separated from one another for a brief period, 
and then allowed to combine and form simpler and more stable com- 
pounds ; owing to the setting free of such energy as has been stored up 
in the highly complex fermentable substance which is no longer required 
to maintain the high level of combination, a certain proportion of this 
energy is released in the form of heat ; the temperature of a fermenting 
fluid is found to rise without the addition of any external heat." 

If to a watery solution of sugar, or an infusion of vegetable juices 
containing sugar, a yeast (a bud-fungus, one of the blastomycetes) be 
added, and the fluid be maintained at a temperature of 35° C, it will 
be found that there is an evolution of gas, which, if passed into lime- 

1 Bacteria and Their Products, p. 87. 



42 BACTERIOLOGY. 

Avater, gives a precipitate — i. e., the carbon dioxid has combined with 
the calcium of the lime-water to form calcium carbonate ; the temperature 
of the solution rises above that of the surrounding atmosphere, and a 
test will show alcohol to be present in the solution and the sugar to have 
largely disappeared. Boiling the solution before adding the yeast does 
not prevent fermentation. Boiling the solution immediately after add- 
ing the yeast prevents fermentation — i. e., boiling the fungus prevents 
its action, its vitality is destroyed. If a quantity of carbolic or sali- 
cylic acid, or mercuric chlorid, be added to the solution, fermentation 
does not occur. If the temperature of the solution be lowered, the 
process is much less active. If the access of free oxygen be prevented, 
fermentation does not occur, which illustrates that in fungi, as in all liv- 
ing cells, the vitality is lessened or destroyed by an insufficient food- 
supply and an unsuitable temperature ; and, finally, it will be noticed that 
after a period fermentation ceases. If after a period some of the yeast 
be removed from the solution, it will be found that it has lost the power 
of inducing fermentative changes in other solutions in which it may be 
placed — it is dead : dead because of an accumulation of its waste-prod- 
uct, alcohol, about it. As with all vital cells, if their waste-products are 
not removed, the cells are smothered in their own excreta. This is the 
example of fermentation usually cited, but very many other types exist. 

If to a solution of sugar a minute portion of the scrapings taken 
from a carious tooth-cavity be added, and the solution maintained at a 
temperature of about 35° C, it will be found, after a time, that the 
solution has acquired an acid reaction, and a chemical test will show 
that lactic acid has formed. A microscopic examination of the solu- 
tion will demonstrate the presence of a large number of the fission- 
fungi forms. As each of these forms has probably its own peculiar 
physiology, several fermentations have been in progress, although lactic 
fermentation predominates. Miller l has shown that this fermentation 
ceases when the amount of acid present exceeds 0.75 per cent., this being 
the excess of waste-products which inhibits the vitality of the fungi. 

These general principles govern the vital processes of all of the 
fungi, including the schizomycetes group, although the several varieties 
of bacteria have peculiar conditions of life which are qualifying clauses 
to the general proposition. 

While it is shown that for the development of the yeast fungus and 
also for many of the bacterial forms the presence of free oxygen is 
essential, there are others which develop in the absence of free oxygen, 
and still others which develop either with or without the presence of 
free oxygen. Bacteria have, therefore, been classified by Pasteur into 
the aerobic, or those requiring free oxygen ; anaerobic, those which 

1 Micro-organisms of the Mouth. 



FERMENTATION. 43 

develop in its absence ; and facultative-anaerobic, those which develop 
with or without the presence of free oxygen — or, 1st, obligatory aerobics ; 
2d, obligatory anaerobics ; 3d, facultative-anaerobics. 

A single species of bacteria rarely or never exists alone in a solu- 
tion of organic matter, except as a result of special precaution upon 
the part of the investigator. Mixed cultures are the rule. When a 
number of species are introduced or are present some develop, others 
are quiescent ; some find conditions favorable to their growth, others do 
not ; but if the conditions be altered, a second or third variety prevails. 
Organisms may find in a field rendered, by an excess of waste-products, 
an improper culture-medium for one form of bacteria, a suitable 
medium in which to grow, so that progressive decomposition occurs 
in the medium. For example, in the successive stages of the 
breaking down of albuminous substances the compounds formed, 
while rendering the soil unfit for the life of the first invading organ- 
isms, fit it for the growth of other varieties, which eifect further 
decompositions. 

By processes of oxidation, reduction, and hydration many forms 
of bacteria eifect a gradual decomposition of albuminous matter. 
Peptones, 1 substances having a less complex composition, are first 
formed ; next, bodies of the compound ammonia type appear, the 
chemical and physiological equivalents of alkaloids derived from the 
higher plants, and hence called ptoma'ins or animal alkaloids. Suc- 
ceeding this, such nitrogenous bases as leucin, ty rosin, and the amins 
(methyl-, ethyl-, and propyl-amin) are formed. Next, fatty acids and 
such acids as butyric, lactic, and succinic, appear ; next aromatic prod- 
ucts, such as indol, phenol, and cresol, are formed ; and the final 
decomposition is represented in the end-products — carbon dioxid, C0 2 , 
hydrogen sulficl, H 2 S, ammonia, NH 3 , and water, H 2 0. 

Several forms of bacteria when grown in solutions of albumin pro- 
duce substances of complex composition which act as poisons when 
introduced into the bodies of animals ; these are termed toxalbumins. 
Many forms of bacteria when introduced in minute quantities into solid 
or gelatinous albuminous matter and kept at a proper temperature are 
found to increase in number ; the gelatinous material around them 
becomes liquefied and undergoes decomposition, with the formation of 
substances which, introduced into living animals, act as poisons. If 
the solutions thus obtained be boiled and filtered, so that they are 
entirely free from the presence of the organisms which produced them, 
and then injected under the skin of an animal, evidences of widespread 
disorder are exhibited — the animal is poisoned. The effects will be 
governed, first, by the nature of the organisms producing the poison, 

1 Ziegler, General Pathology, 1895. 



44 BACTERIOLOGY. 

some producing more virulent substances than others ; and, secondly, 
upon the size of the dose employed. If the effects pass away, the health 
of the animal is restored. If, on the contrary, the organisms them- 
selves be introduced into the body, symptoms of poisoning appear and 
increase in severity, even though but few organisms be introduced. In 
some cases the symptoms persist until the death of the animal ; in 
others they gradually disappear. If a portion of the tissue in which 
the organisms were introduced is used to inoculate other animals, 
similar symptoms appear in them. It is evident, therefore, that bac- 
teria generate in the tissues substances which act as poisons. 

Some species or forms exhibit a predilection for special tissues 
of the body ; for example, a special bacillus develops in the glands 
of the ileum ; others have a predilection for the large intestine, some 
for the spleen, others for portions of the nervous system, and so on ; and 
possibly owing to the peculiar physiological chemistry of the part af- 
fected and to the species of bacteria, specific poisons are generated, 
which, taken into the circulation, produce characteristic symptoms. 

Ferments. — The cells of the living body produce substances which 
have the power of transforming or changing the chemical composition of 
organic matter ; for example, the epithelial cells of the salivary glands 
produce a substance which converts starch, wC 6 H 10 O 5 , into glucose, 
C 6 H 12 6 , a process of hydration. The cells of the peptic glands of the 
stomach produce a substance which changes albumin into peptone, prob- 
ably also a hydration. The cells of the pancreas produce substances 
which cause the hydration of starch and of albumin and the formation of 
leucin and tyrosin. Such substances are known as ferments. They ap- 
pear to take no part in the decompositions which they effect, and are 
called unformed ferments. The small plant-cells — bacteria — also give 
rise to bodies which effect similar changes, or the changes may occur in 
the cells themselves. It is through the agency of these latter substances, 
called " organized ferments," that the decompositions are effected which 
result in the chain of substances described under the decomposition of 
albumin. It is by reason of this property that bacteria act as disease- 
causes, and are capable of disturbing the physiology of the body. 
" When pathogenic fungi succeed in growing in the living body, if 
infection takes place, their action is in general characterized at the point 
of multiplication by degeneration, necrosis, inflammation, and a new 
groAvth of tissue, while the toxalbumins produced by them cause mani- 
festations of poisoning." x 

Many of the forms of bacteria, both saprophytic and parasitic, 
are found in ordinary drinking-water. Many of them, particularly 
the spores of bacilli, are found floating in the air ; the soil to the 

1 Ziegler, General Pathology, 1895, p. 440. 



FERMENTS. 45 

depth of a metre (forty inches) contains numerous varieties. Above 
certain altitudes they are rarely found, and they are rare in the atmos- 
phere of mid-ocean. At ordinary levels in temperate and tropical 
climates they are ubiquitous. They cling to most of the surfaces of 
bodies ; are found on the skin and in its folds ; insinuate themselves into 
the mouths of sweat and sebaceous glands, and swarm in the intestines 
and frequently in the mouths of animals. Among all of the varieties 
thus distributed, there are some which, gaining entrance to the tissues of 
the body, produce destructive diseases — i. e., they are pathogenic. Or- 
ganisms capable of inducing disease-conditions in the body are found in 
all three of the form-groups — cocci, bacilli, and spirilla. Many varieties 
of each of these classes have been shown to possess constant patho- 
genic features, and, further, they have been proved so constant attend- 
ants upon denned diseases that a causative relationship has been made 
out between the organisms and the disease. Special cultures of one 
variety introduced into the body produce always the same symptoms, 
and secondary cultures taken from the diseased organ induce the identi- 
cal disease in other individuals. 

A variety of coccus which when cultivated forms orange-colored col- 
onies, and liquefies the gelatin upon which it is grown, when intro- 
duced into the body is followed by pus-formation — i. e., it is pyogenic 
(from puon, pus, and gennao, I produce). From the manner in which 
the organisms collect into groups they are called staphylococci (from 
staphyle, a bunch of grapes) ; they are thus designated as the staphylo- 
coccus pyogenes aureus, the aureus from the orange color. Another 
pyogenic variety gives white colonies ; hence it is called the staphylo- 
coccus pyogenes albus. Another, producing blue cultures, is called the 
staphylococcus pyogenes cyaneus. Still another, forming green colonies, 
is called the staphylococcus pyogenes viridis. 

Several forms of bacilli have been shown to induce pus-formation ; 
hence are called pyogenic bacilli. 

A specific bacillus has been shown to produce Asiatic cholera, and 
from its form is called the comma bacillus. Another induces breaking 
down of tissue by the formation of tubercles, hence named the tubercle 
bacillus — the bacillus tuberculosis, the exciting cause of pulmonary 
phthisis and of diseases of the skin, joints, etc. To another variety of 
bacillus, typhoid fever is directly traceable. Numerous forms of cocci 
and bacilli when introduced into the tissues are followed by evidence 
of blood-poisoning, or septicaemia (Greek septikos, that which produces 
putrefaction, and haima, the blood). They are the bacilli or cocci of 
septicaemia. Several varieties found in the mouth are capable of causing 
these symptoms, and hence are known as the bacilli sputum septicaemia. 

It is interesting and necessary to note that in many instances when 



46 



BACTERIOLOGY. 



organisms are introduced into the body their action is self-limited, and 
in some cases a body once infected and recovered is insusceptible to 
future introductions of the same organism (see Immunity, Chapter II.). 

Bacteria of the Mouth. 

To the dental practitioner the forms of bacteria which are constant 
and those which are occasional inhabitants of the human mouth are of 
prime interest. Many of the saprophytic fungi are constantly present, 
finding in the food-debris, dead epithelium, abundant moisture, and 
suitable temperature, an extremely favorable soil in which to flourish. 

The other two subdivisions of fungi, in addition to the schizomycetes, 
occasionally develop, as, for example, the bud-fungus (saccharomyces, 
o'idium albicans), which produces in neglected children the form of 
stomatitis called thrush. 

Up to 1885 Miller 1 had isolated twenty-two different forms of 
bacteria from the human mouth. Ten of the twenty-two were cocci ; as 
in Figs. 10-13; some small, some very large. Five were short rods 
(Figs. 14, 15). A curved species, which liquefied gelatin and produced 



Fig. 10. 



a 



Fig. 11. 



• • • 





Fig. 13. 




Fig. 15. 






a 



0* 



Fig. 18. 



Fig. 16. 






Fig. 19. 





Bacteria of the mouth. (Miller.) 

a green coloring-matter, was called vibrio viridans (Fig. 18). Spirilla 
and the leptothrix were found. Of thirty species cultivated later, 
eighteen were cocci, eleven rods, and but one thread form. 

" Of the twenty-two forms first described sixteen brought about an 
acid reaction when cultivated in beef-extract peptone sugar solutions. 
Several of the forms possess the power of converting sugar into lactic 
acid. In some cases the lactic fermentation is attended by the evolution 

1 Micro-organisms of the Mouth. 



BACTERIA OF THE MOUTH. 47 

of gases, C0 2 and H, and if albumin be present H 2 S may be generated ; 
in others there is no formation of gases. There are a number of bac- 
teria which almost invariably occur in every mouth." 
Mouth bacteria proper : 

1. Leptothrix innominata ; 

2. Bacillus buccalis maximus ; 

3. Leptothrix buccalis maxima ; 

4. Jodococcus vaginatus ; 

5. Spirillum sputigenum ; 

6. Spirochete dentium (denticola). 

These are all uncultivable, so that their physiology is not made 
out. Vignal found l among seventeen varieties of mouth bacteria the 
bacterium termo, bacillus subtilis, staphylococcus pyogenes aureus and 
alb us. 

In addition to the forms named, the following varieties of pathogenic 
fungi have been isolated from the mouth : 2 

Micrococcus of sputum septicaemia ; 

Micrococcus tetragenus ; 

Bacillus salivarius septicus ; 

Streptococcus septopyaemicus ; 

Micrococcus gingiva? pyogenes ; 

Bacterium gingivae pyogenes : 

Bacillus dentalis viridans ; 

Bacillus pulpae pyogenes ; 

Pyogenic micrococci ; 

Actinomyces ; 

Saccharomyces albicans ; 

Spirillum sputigenum ; 

Pane's pneumococcus ; 

Bacillus saprogenes ; 

Streptococcus salivarius pyogenes ; 

Coccus salivarius septicus ; 

Micrococcus biskra ; 

Bacillus bronchitidis putridse ; 

Bacillus tussis convulsivse ,* 

Bacillus pneumoniae ; 

Bacillus pneumosepticus ; 

Pneumobacillus. 
Of 111 mice in whose abdominal cavities human saliva was intro- 
duced, but 10 survived, the others dying in from fifteen hours to forty 
days, 42 of them within forty-eight hours. 3 In most of these cases the 

1 Archives de Physiologie, norm, et pathol., 1886, No. 8. 

2 Miller, Dental Cosmos, Nov., 1891. 3 Ibid. 



48 BA CTEBIOLOG Y. 

micrococci of sputum septicaemia were found in a sero-purulent exuda- 
tion in the peritoneal cavity. In 16 cases micrococcus tetragenus was 
present. In over 30 cases cocci, staphylococci, streptococci, and diplo- 
cocci were present. 

Miller divides the organisms into two classes, according to the 
mode of death of the animals attacked : first, those which produce 
speedy death through blood-poisoning with but comparatively slight 
local reaction ; secondly, those which induce fatal pyogenic processes 
at the point of injection. 

To recapitulate : the human mouth swarms with bacteria of the 
several classes ; lactic, acetic, and butyric acid ferments ; numerous 
saprophytic fungi ; and organisms producing specific disease-conditions 
when introduced into the tissues. The pyogenic organisms are almost 
constantly present. 

Phagocytosis. 

The tissues of the body do not play an entirely passive part in 
the diseases caused by bacteria. While many tissue-cells of the body 
exhibit a resistance to and in some cases wage a warfare against invad- 
ing organisms, the resistance is much more marked in some instances 
than in others. It had been observed, I860-' 70, by von Reckling- 
hausen, Rindfleisch, Ponfincks, and others, that certain cells of the 
body took into themselves particles of dust and the material of dis- 
integrated blood-corpuscles. In 1874 Ziegler observed the fibroblasts 
of granulation-tissue take up and destroy leucocytes — devour them. 
The wandering cells of the body, loaded with dust-particles and other 
foreign matter, appear upon the surface of mucous membrane. 

In 1884 Metchnikoff l published the results of a series of studies 
made by him, principally upon the Daphnia, small fresh-water Crus- 
tacea. He observed that when the spores of the monospora cuspidata, 

Fig. 20. 





1, a spore which has penetrated the intestinal wall and entered the abdominal cavity, where four 
leucocytes have surrounded its end : m, the muscular layer of the intestine ; e, epithelial layer ; 
s, the serous layer. 2, a spore surrounded by leucocytes from the abdominal cavity of a Daphne. 
(Metchnikoff.) 

a bud-fungus, gained access to the alimentary canal of the animal it 

1 Fortschritte der Med., Bd. ii. See Comparative Pathology of Inflammation (same 
author). 



PHAGOCYTOSIS. 



49 



Fig. 21. 



passed into the abdominal cavity through the intestinal walls. As soon 
as it entered the cavity it Avas attacked by leucocytes (Fig. 20), which 
took the spores into their bodies, and devoured and digested them. 1 " If 
the Daphnia is healthy, the monospora is gradually overcome ; bat if 
the animal be feeble or the monospora is ingested in very large quan- 
tities . . . the animal may eventually succumb to the attack.'' 

The wandering cells of the body have also been shown to possess this 
power, which MetchnikofF has termed Phagocytosis — phago, I eat, and 
cytos, a bud (see Inflammation). 

The reasons set forth by MetchnikofF, that this is Nature's means 
by which the living tissues defend themselves against invaders, and that 
these cells are specifically designed for this purpose, require modifica- 
tion. It is probably an expression of the nutritive function of simple 
cells. The process is not universal throughout the body, for in some 
instances the bacteria are taken up by the leucocytes, and in others they 
are left undisturbed. 

Researches of Leber, Buchner, and others have shown that leucocytes 
may be repelled by certain chemical 
substances and attracted by others. 
This property of attraction and re- 
pulsion has been termed chemotaxis ; 
positive when attraction exists, neg- 
ative when there is repulsion. Buch- 
ner found that substances derived from 
certain bacteria, even in high dilution, 
possessed positive chemotactic prop- 
erties, and that certain organic deriv- 
atives, such as methylamin, leucin, 
tyrosin, and urea, exhibit negative 
chemotaxis. 2 

It is beyond question that phago- 
cytosis plays an important part in the 
prevention of disease and the removal 
of foreign substances which gain ac- 
cess to the tissues, or are formed in 
the body. It is not the leucocytes 
alone which possess this power (Fig. 
21 ). The endothelial cells of blood- 
vessels have this function, as have 
several other forms of mesodermal cells (MetchnikofP), notably the 
wandering corpuscles of connective tissue. 

1 Woodhead, Bacteria and Their Products, 1891 ; and MetchnikofF, Ibid. 

2 This subject is discussed at length in Ziegler's General Pathology, 1895. 
4 




Active phagocytosis. Endothelial cells en- 
closing the bacilli of swine septicaemia, 
from an hepatic vein of a pigeon : a, endo- 
thelial cells ; b, leucocytes. (Metchuikoff.) 



50 BA CTERIOL OGY. 

Hugenschniidt l has shown that the filtered saliva of the human 
mouth, containing necessarily quantities of bacterial products, possesses 
marked positive chemotactic properties. 

Nuttall 2 showed that the filtered serum of the blood possessed bac- 
tericidal power, and that degeneration of ingested bacteria occurred be- 
fore the process of phagocytosis. Buchner found that the activity of the 
serum against bacteria was greater when deprived of its cellular elements. 
Boiling for half an hour destroyed the property. By dialysis or ex- 
treme dilution with distilled water its germicidal energy was checked ; 
but if an equal dilution was made with sodium-chlorid solution (0.6-0.7 
per cent.), the bactericidal power was not lost. Hankin, 3 Ogatta, and 
others have isolated from the spleen, lymphatic glands, and blood, glob- 
ulins which in solution have germicidal power. Buchner has suggested 
that these germicidal substances be called " alexins." Noting the con- 
ditions under which serum germicides are observed, Vaughan 4 and also 
Halliburton 5 conclude that the substance to which the germicidal 
power is due is a nuclein. 

1 Dental Cosmos, vol. 38, p. 797 et seq. 

2 See Abbott's Principles of Bacteriology, p. 425. 3 Ibid. 

4 Ptoma'ins and Leucoma'ins. 5 Chemical Phys. and Path. 



CHAPTER IV. 



DISTURBANCES OF NUTRITION : ATROPHY, DEGENERATION, 
NECROSIS, HYPERTROPHY, TUMORS. 

Owing to various disease-causes to which the tissues of the body 
may be subjected, they may suffer an alteration in the normal con- 
tinuity of the cycle represented by development, growth, maintenance, 
and that gradual lessening of vitality which precedes the death of an 
individual. If there be such interference with the process of develop- 
ment that an organ is much below normal in size, the condition is 
spoken of as aplasia or agenesia. If the interference merely checks the 
growth of a developed organ, the condition is known as hypoplasia. 1 
It is with disturbances arising during the period of maintenance that 
this chapter is concerned. 

Disorders of nutrition are of two classes : in one class there is an 
excess of nutrition ; in the other there is a deficiency. In either 
class disturbance in the nutritive equilibrium alters the vitality of 
tissue-cells. In one case, if stimulation be the process in operation, it is 

Fig. 22. 
Health 



g . 


Stimulation / 


y. (Sedation) 

\ Atony 


o 

to 

•<s> 

25 -IS 


Irritation / 






(Hyperaemia) 
Inflammation 






\ Degeneration 
Atrophy 


( Degeneration) 
Overwork-Paralysis 






Paralysis -Starvation 



fca 



££ 

is- 

o 
3 



Death (Necrosis) 

but a question of time and degree until the death of the cells is brought 
about. In the other case, if sedation be the influence at work, it is also 
but a question of time and degree until the cells succumb. The extent 
of the degree of interference with nutrition, whether hyper- or hypo- 
nutrition, depends upon the extent of the influence in operation, the 

1 Ziegler, General Pathology, 1895. 

51 



52 DISTURBANCES OF NUTRITION. 

effects ranging from slight disturbance of function to death of a part. 
The nature of these effects is graphically represented in Fig. 22. The 
two horizontal lines farthest separated represent health and death. 
Descending from the health-line to the death-line are the curved lines 
of a semi-ellipse, the path from health to death being a gradual, not a 
precipitate fall to death, in conditions of altered nutrition. It will be 
observed that these curved lines are crossed at intervals by straight 
horizontal lines, which represent stages in the vital descent, or grades 
of nutritive disturbance. If a general survey be taken of these several 
stages, based upon the observed phenomena of cell-life, deductions as 
to the nature of the alterations of physiology occurring may be made as 
illustrative examples. 

Hypernutrition. 

The effect of stimulation, first, upon the functions of organs, and, 
pari passu, upon their vascular supply (see Chapter V.), is represented 
by an increased nutrition. The irritability, contractility, and general 
functional activity of the part are increased. More food is appro- 
priated, oxidation is increased, and hence more energy is set free and 
more work is done. Stimulation is therefore followed by an increase 
of functional activity. If the functions of the part be secretory, secre- 
tion is increased. Connective-tissue cells, whose function is the forma- 
tion of basis-substances, form them in increased amount. Increase the 
stimulation, and the effect is one of irritation : vital processes become 
fretful, incomplete chemical changes occur in the cells, and functional 
activity is disordered. The energy developed in the cells of tissues 
manifests itself in nutritive, functional, or reproductive activities (Vir- 
chow), and hence, as the energy is developed in definite amount, if it be 
expended in one of these three directions, the other two must be corre- 
spondingly diminished. Thus irritation may be followed by increased 
secretion or functional activity, an altered metabolism in the cells ; or 
the cells may exercise their reproductive function, in which case the 
number of cells is increased — i. e., a part becomes hypertrophied. 

HYPERTROPHY OR HYPERPLASIA. 

By hypertrophy is meant an increase in the size of some organ, or 
portion of it, or of any tissues. Hypertrophy may be either simple or 
numerical. Simple, when the increase of volume is due to an increase 
in the size of cells ; numerical, when due to an increase in the number 
of cells. 

Causes. — Hypertrophy occurs when nutrition in a part exceeds the 
waste. In general terms, it is caused by a continued irritation of 



HYPERTROPHY OR HYPERPLASIA. 



53 



definite grade. It is, as a rule, intimately associated with a parallel 
increase in the local circulation of a part (see Chapter V. and Fig. 22). 

Hyperplasia is frequently a reflex nutritive change due to an increased 
demand for Avork being made upon tissues ; for example, when a muscle 
is repeatedly urged to an unusual amount of work short of marked 
fatigue, an increase in its function occurs, its capacity for work becomes 
greater, and if the strong stimulus (mild irritation) implied be con- 
tinued, the cells increase in size, and, it may be, in number : all three 
phases of the expenditure of an increase of vital energy being repre- 
sented — functional, nutritive, and reproductive. This is also repre- 
sented in the reaction of the alternately acting and resting heart-mus- 
cles. If an unusual and continuous strain be placed upon the heart 
owing to an increase in the resistance it is normally called upon to 
overcome, an increase of the volume of the muscles follows. 

Tissues or organs accustomed to performing work, if deprived of 
the work, use the developed vital energy in reproduction, and hyper- 
trophy results. For example, upon the roots of teeth which have lost 
their antagonists the pericementum, deprived of its normal exercise, fre- 
quently forms hypertrophic growths of cementum upon the tooth-roots. 
When tissues accustomed to mechanical resistance due to their anatomi- 
cal forms are freed from this resistance, they frequently hypertrophy in 
the direction of the accustomed resistance. 

There is a form of cellular hypertrophy noted in some pathological 
states which should be mentioned in this connection, viz., under some 



Fig. 23. 




d d 

Dog's hair encapsulated in subcutaneous tissue : o, hair ; b, fibrous tissue ; c, proliferating granu- 
lation-tissue ; d, giant cells. Preparation hardened in alcohol, stained with Bisniark-brown, 
and mounted in Canada balsam. X 66. (Ziegler.) 

forms or degrees of irritation, an increase in the size of cells may be 
noted characterized by incompleteness of formation ; the nuclei of cells 
initiate the reproductive process, but it is incomplete. The nucleus 
divides, but the cell-body fails of division, the new nuclei subdivide, and 
the enclosing cell increases in volume, forming a giant or multinucleated 
cell. These cells appear where tissue is to be removed physiologically, 
as the roots of deciduous teeth. They are found about foreign bodies 
which have found entrance to tissues, about ligatures, dead tissues, etc., 



54 DISTURBANCES OF NUTRITION. 

provided bacterial infection has not occurred and caused active inflam- 
mation. Their origin is probably from leucocytes and wandering tissue- 
cells, which, having undergone this peculiar variety of reproductive 
change, forming large multinucleated cells, and having their phago- 
cytic property much increased, devour and remove many foreign sub- 
stances. 

It is probable that a similar condition exists about the root of an 
implanted tooth. The irritation caused by the presence of the foreign 
body causes cell-reproduction, complete in some cases, incomplete in 
others, the foreign substance being surrounded by a collection of embry- 
onic cells. Some foreign bodies are devoured, others resist solution. In 
the first case, as soon as the foreign body is disposed of, the cells take 
on constructive, formative action, and are transformed into repair- tissue. 
In the second case, failing to remove the intruder, the cells may acquire 
a modified tolerance of it, and connective tissue may be developed 
around it — i. e., it is encapsuled. 

TUMOR-FORMATION. 

Hypertrophy and hyperplasia are expressions of a degree of the 
reproductive function, physiological in character, having in the majority 
of cases well-defined causes, and serving an economic end in the body. 
There is another form in which there is an excessive activity of the 
cell-property, the reproduction being wholly malign in character, its 
products serving no physiological end ; on the contrary, threatening 
life in the degree and rapidity of reproduction. Such reproductive 
forms are known as tumors. According to the etymology of the word, 
any swelling is a tumor (tumeo, I swell) ; but in its pathological 
sense the term is restricted to growths comprised under the follow- 
ing head : " A new formation of tissue possessing an atypical struc- 
ture, not exercising any function or service to the body, and pre- 
senting no typical limit of growth." 1 This morbid reproductive process 
and consequent overgrowth may affect any of the tissues of the body. 
The growths may be divided into two great classes : first, those of the 
connective-tissue type — bone, cartilage, muscle, or ordinary connective 
tissue in any stage of its development ; secondly, those of the epithelial 
type, arising from any epithelial structures — that is, any of the struc- 
tures which arise from the epiblast or hypoblast of the germinal layers ; 
the connective-tissue tumors are those composed of tissues derived from 
the mesoblastic layer. 

Tumors may be clinically divided into two groups, according to their 
influence upon the life of the individual : first, benign tumors, or those 
whose growth is not a menace to life ; secondly, malignant tumors, or 

1 Ziegler. 



TUMOR-FORMA TION. 55 

those which threaten the life of the individual affected. Malignant and 
benign tumors are found in both classes, connective tissue and epithelial. 

The growth of a tumor is attended by a sapping of the vitality of a 
sufferer — the degree of the debility produced being apparently in direct 
ratio to the size and the rapidity of the growth. Besides the size and 
the rapidity of development of individual tumors, another element deter- 
mines their malignancy, their position, and, furthermore, their occurrence 
in other parts, resulting in multiple tumor-formation. A tumor-victim 
acquires a peculiar appearance — a cachexia, whose intensity and rapidity 
of advance are directly dependent upon the degree of malignancy. 

Tumors introduce no new form of tissue-element ; they are repro- 
ductions of the cells of the tissues of the body. They may have the 
same cell-formation as the tissue from which they spring, and are then 
called homologous tumors ; or they may have a different histological 
structure from the tissue in which they are found, being then called 
heterologous tumors. For example, a bony tumor growing from bone 
would be homologous ; a cartilaginous tumor growing from gland-tissue 
would be heterologous. 

Causes. — The causes of tumor-formation are unknown ; it has been 
believed that their growth is due to parasites ; this however has not been 
proved. A certain proportion of tumor-formations, 7-14 per cent., 1 
appear to be caused by traumatic injury ; as, for example, in cases of 
mammary tumor a history of a blow or fall may be at times obtained. 

Long-continued, sluggish inflammation appears to be causative of 
tumor-formation in an unknown percentage of cases. A chronic irritation 
of certain portions of the body, such as the junction between the mucous 
and skin surfaces of the lip, the sides of the tongue, etc., is a frequent 
antecedent to their formation. Ziegler gives a reasonable explanation 
of the origin of certain epithelial tumors in organs which are under- 
going atrophy ; for example, in advanced age the connective tissue of 
the body is undergoing atrophy and there is relaxation of its strata ; the 
epithelium of the surface (or of glands), still possessed of its power of 
reproduction, proliferates and invades the connective tissue, producing 
cancer. 

Tumor-formation consists in the reproduction of the cells of one or 
more tissues, and in the growth thus formed bloodvessels are developed. 
Tumors do not contain nerves. 2 Their blood-supply, however, is gen- 
erous, so that for long periods a superabundance of nutritive material 
is carried to them ; but after a variable period, depending upon the 
type of growth, the nutritive supply becomes disordered and degenera- 
tions occur. 

About the more slowly developing tumors a condensation of connec- 

1 Ziegler. 2 Green's Pathology and Morbid Anatomy, 8th ed. 



56 BISTUBBANCES OF NUTRITION. 

tive tissue occurs in many cases, forming a distinct limiting wall or cap- 
sule from which the tumor may be enucleated. 

The two great classes of tumors, those of mesoblastic and those of 
epi- and hypoblastic origin, may be subdivided into orders according to 
their histological peculiarities. 

Class One. 1 
tumors of mesoblastic tissues : 

Order One. 
Tumors of mature connective tissue. 

Bony tumors, or Osteoma. 
Cartilaginous tumors, or Chondroma. 
Fibrous tumors, or Fibroma. 
Fatty tumors, or Lipoma. 
Mucous tumors, or Myxoma. 
Lymphoid-tissue tumors, or Lymphoma. 

Order Two. 
Tumors of the embryonic connective tissues : 
The fleshy tumors, or Sarcoma. 

Order Three. 
Tumors of the higher tissues : 

Tumors of muscle, or Myoma. 

Tumors of nerves, or Neuroma. 

Tumors of bloodvessels, or Angioma. 

Tumors of lymphatic vessels, or Lymphangioma. 

Class Two. 
tumors of epiblastic and hypoblastic tissues : 

Papilla of skin and of mucous membrane, or Papilloma. 

' f Adenoma. 

Tumors of glandular tissues ^ 

& [ Carcinoma. 

A separate class of tumors includes congenital mixed tumors, or 
Teratomata. The tumors of epiblastic and hypoblastic type are some- 
times called Epitheliomata, for epithelial tissue is their characteristic his- 
tological structure. 

Malignant tumors are found in both of the great classes, mesoblastic 
and epi- and hypoblastic. Carcinoma represents the type of malignancy 
1 Modified from Green's Pathology, p. 14S. 



TUMOR-FORMA TION. 



57 



in the epithelial tumors. The sarcomata are the malignant tumors of 
the connective-tissue type. 

Tumors are rarely composed of but one type of tissue ; several types 
may be present, the tumor receiving its name from the tissue predom- 
inating. When the distinguishing feature of a tumor is two predomin- 
ating tissues, the tumor is given a compound name ; as, for example, 
when, in a sarcomatous growth, numerous large multinucleated celLs char- 
acteristic of bone-marrow are found, it is called a myeloid sarcomatous 
tumor. When fibrous and sarcomatous tissues are distinguishing feat- 
ures the tumor is called a fibro-sarcoma. 

Since the malignancy of a tumor is due primarily to the size and the 
rapidity of its growth, it is clear why sarcomata are more malignant 
than fibromata, and why some forms of sarcoma are more malignant 
than others. To illustrate : 

Begin observation at the indifferent stage of connective-tissue de- 
velopment, when connective-tissue cells have first divided, reproduced ; 

Fig. 24. 




Porcine embryo : ct, embryonic connective tissue of mesoblast. 2 l / z cm. X 250. 



the tissue produced, seen in granulation-tissue and in the embryo, is at the 
indifferent stage, as seen in section of the embryonic jaw (Fig. 24). 

Mesoblastic cells at this early period are in an indifferent stage ; some 
of the cells shown in the figure will form bloodvessels, others will become 
bone-corpuscles, others will form fibrous and others muscular tissue. 
This structure has its analogue among tumors in a soft, fleshy, rapidly 
growing growth, called the round-celled sarcoma. As cells expend their 
vital energy in three ways (nutritive, functional, and reproductive ac- 
tivity), the embryonic cells of such a growth may expend their energy 
in nutrition (growth), and will then grow out of the indifferent stage 
into a more mature form of connective tissue, the ultimate form of one 
type being a fibre, an embryonic round cell undergoing a series of form- 



58 



DISTURBANCES OF NUTRITION. 



changes from a small round cell to a long fibre (Fig. 25). The growth 
may cease at any stage of this form-change, the tumor composed of such 
cell-forms receiving a corresponding name. The embryonic connective- 
tissue tumors, as stated, are called sarcomas, the form of the cells com- 
posing them giving them a qualifying title. 

In Fig. 25 are represented the stages of development of a connec- 
tive-tissue hbre from a round cell. If growth cease at stage 1, and the 



Fig. 25. 



1 2 

® ® 



cell-energy thereafter expend itself in reproduction, a rapidly growing 
tumor composed of small round cells is formed — a small round-cell 
sarcoma, markedly malignant. If the cells expend a portion of energy 
in growth of cell-size, a large-cell sarcoma is formed, less malignant 
than the former. If the cells expend a portion of their energy in form- 
ing intercellular substance (reproduction), malignancy is less active. 
So the spindle-forms, 3 and 4, represent less rapid reproduction and lesser 
malignancy than 1 and 2, although the form 4, which should be of less 
rapid reproduction than 3, because of more mature organization, is fre- 
quently more malignant, because less intercellular substance is formed, 
as shown in Figs. 26 and 27, the energy represented in that process 

Fig. 27. 



Ftg. 26. 





Small spindle-celled sarcoma (from a 
tumor of the leg). X 200. 



Large spindle-celled sarcoma. To the left the cells have 
been separated by teasing, so that their individual 
forms are apparent ; to the right, they are in their 
natural state of apposition, such as would be seen in 
a thin section of the tumor. (Virchow.) 



being used up in reproduction. The nearer the approach to the mature 
form, (6, Fig. 25), the slower the growth of the tumor, which, when 
composed of tissue of this type, loses its fleshy (sarcomatous) appearance 
and becomes fibrous, and is hence called fibroma. 

When a sarcoma begins its growth from bone its histological char- 
acter is frequently modified (Fig. 28). It contains large marrow-cells 









> - ■ - 






s. 







■ 



s- *S 



. 






career. M ^ 

-- 
Z"_t^t.:a_ rumors — _ : -- wtfa> arising firom epi- }r bypoblasi ; : — 
- se z pn -it. ^ 

mm. - - smmoandc 







I 






t&£ EK Q3B - 









60 



DISTURBANCES OF NUTRITION. 



Fig. 30. 




tissue, which possess the characteristics of epithelium developing with- 
out the limitations of a basement-membrane. Beginning upon a skin, 

or mucous surface, or in a gland, the re- 
produced epithelial cells are not sharply 
marked off from the connective tissue by 
a limiting membrane, but gaining en- 
trance to the alveoli of connective tissue, 
they proliferate there, find their way into 
lymphatic vessels and lymphatic glands, 
and reproduce epithelial growths in such 
places of lodgement, so that a tumor hav- 
ing its origin in one part may give rise to 
tumors in other parts of the body (Fig. 
30). 

Like the connective-tissue tumors, types 
of carcinoma differ as to rapidity of growth 
in their original situation and in the degree 
of transference ; these factors determine 
their malignancy. Tumors of the sar- 
coma group may also give rise to growths 
in other parts, the tumor-cells being car- 
ried thence by lymph-vessels or bloodvessels. 

After a period, tumors frequently suffer such interference with their 
nutrition that degeneration occurs in them. 

After removal, some varieties of tumors, both those which infiltrate 
surrounding tissues and those which are metastatic (or transferred from 
the original to other sites), show a tendency to recurrence ; that is, 
removal does not effect a cure, and the tumor may upon reappearance 
assume another and a more malignant character. 

Epithelial tumors never become tumors of the connective-tissue 
type ; and, vice versa, connective-tissue tumors cannot become epithelial 
tumors. The distinction formed between epiblast and mesoblast in the 
embryo is maintained throughout life. 



Section through an aggregation of 
very young cancer-cells, lodged 
like an embolus within a capillary 
of the liver. The parent growth 
was an adenocarcinoma of the 
stomach. Preparation stained with 
hematoxylin. X 300. (Ziegler.) 



INFLAMMATORY DEGENERATION. 

If the degree of irritation causing an increased activity of the repro- 
ductive function be exceeded, the entire nutritive balance of a part be- 
comes disturbed in a violent manner ; the vascular disturbance accom- 
panying hypertrophic processes becomes much exaggerated in the 
tissues in the area involved. The nutrition of the cells of the part 
appears to be in abeyance, and vitality' in them ceases ; the protoplasm 
has lost its character, and in the affected area a collection of embryonic 
cells is found ; this is the condition described in the next chapter under 



HYPON UTRITION—DEGENERA TIONS. 6 1 

the head of inflammation. The final stage of overstimulation has been 
reached — death by overwork. 

Hyponutrition. 

If the nutritive balance be disturbed upon the minus side, it amounts 
to the application of a sedative influence in varying degrees. As in the 
cases of hypernutrition, the stages or degrees of hyponutrition are 
intimately associated with the conditions of the vascular supply — its 
quality and its quantity. The first stage of hyponutrition is comprised 
in an atony, a lessened activity of the vital processes of a part. Cell 
chemistry is disordered, less oxidation occurs, hence a lessened heat- 
production ; the function of the cell is diminished ; if secretory, its se- 
cretion is lessened ; if muscular, the cell has lessened contractility ; the 
relations between nutrition and waste are disturbed ; the part becomes 
physiologically wearied sooner than usual. 

ATROPHY. 

Causes. — If the disturbance in the nutritive supply be continued or 
be in more marked degree, the nutritive processes in cells become dis- 
ordered, so that more cell-substance is broken down than is replaced by 
pabulum ; that is, waste exceeds repair, and the part affected becomes 
diminished in size — L <?., becomes atrophied. The atrophy may occur 
either because the food-supply is insufficient, or because the cell has 
undergone such change that it is not able to use its nutriment when 
present in proper quantity and quality. Atrophy is, however, more 
often traceable to an improper food-supply, or an excess of waste, than 
from any clearly made-out fault in tissues. A common source of insuf- 
ficient food-supply is interference with the vascular supply to a part. 
It may be any of the causes (see Chapter V.) which lessen the size of 
the artery supplying a part. 

Disuse of a part may be followed by a diminution of its vitality : 
it becomes atonic, and then atrophies. The atrophy is proportionate to 
the extent of the disease. Atrophy of organs may be a part of the 
cycle of life ; as, for example, atrophy of the thymus gland in children, 
and atrophy of the mammary gland in the female after the menopause. 
Many atrophies of this type are properly termed resorptions ; as, for 
example, in the thymus gland when the entire gland is removed. The 
loss of the roots of deciduous teeth and the loss of the alveolar process 
after teeth have been lost are examples of tissue-loss through resorption. 

DEGENERATIONS. 

If the nutritive balance be disturbed through intrinsic defect of cells, 
or through a further disturbance in the character or the amount of the 



62 



DISTURBANCES OF NUTRITION. 



food-supply, the vitality of the cells undergoes more marked change. 
The character of the cell itself becomes altered, its chemical pro- 
cesses are markedly deranged, and changes in the cell-substance 
itself may be noted. The function of a part is impaired and 
soon ceases entirely. This is a cell-degeneration proper. Such pro- 
cesses are usually accompanied by shrinking in the size and diminution 
of the number of cells in a part ; that is, degeneration and atrophy are 
processes commonly associated. In an actual degeneration the proto- 
plasm itself becomes altered in character ; the proteids of which it is 
composed are in part transformed into other substances. 

There is another type of degeneration in which the protoplasm does 
not seem to have changed its chemical character, and yet foreign sub- 
stances make their appearance in tissue and atrophy of its cellular ele- 
ments follows. 

True Degeneration. — The first type of cellular degeneration is that 

Fig. 31. 




Cloudy swelling of kidney epithelium : a, normal epithelium ; b, epithelium beginning to be 
cloudy ; c, advanced degeneration; d, cast-off degenerated epithelial cells. From a preparation 
which had been treated with ammonium chromate. X 600. (Ziegler.) 

called cloudy swelling. The contents of a cell become markedly granu- 
lar, hence the name of the condition, granular degeneration, and the 
cell increases in size. " This change is to be regarded as a disorganiza- 
tion of the cell-protoplasm following the absorption of liquid into its 
substance, and leading to a partial separation of its solid and liquid con- 
stituents. The cell may recover ; but there is often complete destruc- 



DEGENERA TIONS. 



63 



Fig. 32. 




Muscular tissue of the heart 
(from a case of severe ty- 
phoid fever) : the fibres are 
granular, the nuclei ob- 
scured, and the striation 
lost. X 400. 



tion, the cell ultimately breaking down into finely granular fragments." l 
This is the parenchymatous degeneration found 
in continued fevers. 

" It may be regarded as the first step toward 
fatty metamorphosis." 2 

Patty Degeneration. — Fatty degeneration is 
a condition in which an accumulation of fat is 
found in the substance of cells as the result of 
partial decomposition of cell-substance itself. 

Causes. — Fatty degeneration results from 
great disturbance in the nutritive balance of 
cells ; that is, the cause of fatty degeneration is 
a high degree of disturbance of cell-nutrition. 
" The larger the amount of cell-albumin replaced 
by fat, the nearer is the whole cell to death." 3 
Depressed vitality is always the proximate cause. It may be produced 
by improper food-supply and by changes in the vital powers of cells, 
or it may be an expression of the natural decadence of cells. 

Disuse of a part which has normally an active physiological func- 
tion is not infrequently folloAved by a degeneration of cell-substance and 
an associated atrophy of the part. 

Mechanical interference with the blood-supply of a part is a prolific 
source of fatty degeneration of its cells. When the walls of vessels 
have undergone the changes known as atheroma and calcareous 
degeneration (which see), the arterial (food) supply to the tissues 
involved becomes much impeded. This change, occurring usually at 
a time of life when cell-vitality is on the wane, is followed by faulty 
metabolism in the cell ; there is not that complete chemical interchange 
which occurs in normal metabolism, and degeneration occurs. When the 
coronary arteries of the heart become atheromatous fatty degeneration 
of the heart-muscle follows. 

When the blood is deficient in quality, as in the several forms of 
anaemia, particularly pernicious anaemia, fatty degeneration and atrophy 
of organs may result in consequence of the faulty nutrition. 

Fatty degeneration is one of the consequences of faulty oxidation in 
tissues, which explains its occurrence in the above-mentioned conditions, 
and it in turn lessens the oxidizing power of cells, the resulting cellular 
debility interfering with such processes as regeneration or the repair of 
tissues. 

Fatty degeneration is the fate of nerve-fibres which have been sev- 
ered from connection with their nerve-centre. 



1 Ziegler's General Pathology, 1895. 

2 Green's Pathology and Morbid Anatomy, 1895. 



Ibid. 



64 DISTURBANCES OF NUTRITION. 



* 




In addition to the fatty metamorphosis which occurs in tissue- 
cells as the result of faulty metabolism, this change of cell-albu- 
min also occurs in other pathological states ; for example, the cells in 
certain inflammatory effusions undergo fatty metamorphosis. 

The process occurs in the cells of tumors Avhen the growth of their 
vascular supply does not keep pace with the volume of the tumor. 

A peculiar change sometimes takes place in portions of tissue which 
have suffered fatty degeneration, the change affecting particularly parts 
which have degenerated in consequence of the presence of the bacillus 
tuberculosis. The presence and proliferation of the bacillus in tissues 

appear to be attended by phagocytic 
FlG - 33 - action (see Chapter III.) upon the 

^®ifJrW^^^A^ ^ part of the cells about them. The 

^^^J^^^^^^^tf^^ irritation resulting from the action 

of the bacillus causes incomplete re- 
productive activity in the cells, and 
multinucleated cells are formed. The 
bacilli are taken into the bodies of 
these cells, the irritation set up caus- 

'i^^SS^^^'^ m £ (^' 1 ^' ^) an emigration of leuco- 

„, . , . .,,?^. . . „ „ . . cytes from the adjacent vessels which 

Tubercle bacilli in giant-cell (from tuber- J •> 

cuiosis of horse), x 600. (Cheyne.) occupy the connective-tissue spaces ; 

the accompanying effusion solidifies, 
and in the affected spot is formed what is termed a tubercle. The cells 
after a period may undergo fatty degeneration, and following this the 
mass is transformed into a cheesy substance, in consequence of which 
the process is called caseation. 

In apoplectic effusions into the brain-substance the effused blood and 
part affected undergo fatty degeneration and caseation. 

It not infrequently happens that in these caseous masses calcium 
salts are deposited. At times the entire mass may, from some unknown 
cause, excite active inflammation. 

Fatty Degeneration of Vessels. — The occurrence of fatty 
degeneration of the heart-muscle due to obstruction in the coronary 
arteries has been alluded to. A similar condition mav occur in the 
muscle-fibres of the middle coat of bloodvessels. It occurs most fre- 
quently in the internal, the endothelial coat, or the tunica intima of 
vessels. Droplets of fat are formed in the endothelial cells lining the 
vessels. " In the smaller arteries the fatty degeneration is more liable 
to affect the external coat." * In some forms of nephritis (Bright' s dis- 
ease) fatty degeneration affects the endothelial cells of the capillary 
vessels, leading to their rupture. 

1 Green's Pathology and Morbid Anatomy. 



BE GENERA TIONS. 6 5 

Mucoid, Colloid, and Hyaline Degeneration. — The albumin of 
cells may undergo other chemical changes than transformation into 
fatty substances ; they may undergo mucoid, colloid, or hyaline trans- 
formation. The causes of the degeneration are not made out. The 
function of the part affected is destroyed. 

Lardaceous Degeneration. — This type of degeneration is known 
as amyloid, albuminous, or waxy. The formation of the material from 
which this condition derives its name is preceded by an unknown type 
of degeneration of the cells of the part affected. The degenerative 
processes appear to be the result of long-continued suppuration due 
usually to tubercular diseases. In the connective tissue about the 
degenerated cells a substance akin to albumin is deposited, which causes 
swelling and a pseudo-hypertrophy of the organ affected. The substance 
gives a reaction with iodin resembling that of starch, hence the name 
amyloid (amylum, starch). It may affect any organ of the body. It 
usually appears first in the connective tissue lying between the inner 
and middle coats of small arteries. The swelling caused by the infiltra- 
tion markedly lessens the calibre of the vessels and diminishes the 
nutritive supply of the parts supplied by the artery, which may lead 
to fatty degeneration and atrophy of the insufficiently nourished 
parts. 

Calcareous Degeneration. — This condition must be clearly distin- 
guished from ossific or bone-forming changes which occur in tissues. 
In bone-formation there is a constructive process in which cells build a 
definite type of formed material. In what is called calcareous degen- 
eration there is a deposit of calcium salts, mainly the phosphate and 
carbonate. In bone-formation the lime salts are combined in a definite 
manner with an albuminous basis (see Calco-globulin). The phosphates 
and carbonates of calcium and the carbonate of magnesium are held in 
solution in the serum of the blood by virtue of the carbon dioxid in 
the blood. It is believed that the deposit of calcium salts in a tissue is 
more than a mere precipitation, and that calcification results from the 
combination of the salts with an albuminous base and with fatty acids. 
These deposits occur in tissues which are in a degenerative or dying 
state. They follow frequently as a secondary state upon fatty degen- 
eration, caseation, and hyaloid degeneration of tissues, particularly of 
connective tissues. A similar deposit occurs in the affected joints in 
gout, when sodium bi urate is deposited in the affected tissues. This is 
particularly notable in the walls of bloodvessels which have suffered 
previous degeneration. 

The changes which pronounced degeneration or death of cells brings 
about in tissues appear to create an affinity between such substances and 
the calcium salts of the blood, so that they form intimate compounds. 

5 



6Q DISTURBANCES OF NUTRITION. 

The deposits may be in the cells themselves, as well as in the intercellu- 
lar substance. They affect particularly the white fibrous connective 
tissues. What appears to be a cardinal principle in these calcic deposits, 
is the formation of substances during or following degenerative changes 
in parts having a sluggish circulation, which substance renders insoluble 
the calcium salts held in solution by the carbon dioxid of the blood, or 
possess a stronger chemical affinity for the salts than the carbon dioxid 
which holds them in solution. 

Calcification of Arteries. — In or during the series of nutri- 
tional disturbances associated with senility, the degeneration of tissues 
accompanying old age, calcareous deposits may occur in the middle coats 
of arteries, transforming these normally elastic tubes into rigid tubes of 
lessened calibre. Such arteries cannot perform their normal function in 
regulating the blood-current, and parts supplied by them suffer more or 
less nutritive disturbance and in some cases actual death. Calcareous 
areas frequently form in such portions of arteries as have suffered from 
an inflammatory degeneration of the tissues of the deeper layer of the 
inner arterial tunic (i. e., atheroma). 

NECROSIS. 

When the depression of vital activities due to disturbance of the 
nutritive balance becomes more marked than those grades productive 
of atrophy and degeneration of a part, the vital processes of the cell 
are paralyzed — it dies from starvation, the condition being called necro- 
sis, from nekros, dead. 

Causes. — The conditions which bring about a cessation of vitality in 
the cells of tissues may be grouped under two heads : l 1st. Interference 
with the supply of nutritive material ; 2d. Destruction of the vital 
activity of cellular elements. 

Class I. — Necrosis arising out of the first group is caused by ob- 
struction of the vascular supply, through occlusion of arteries, veins, or 
capillaries. 

1st. Obstruction of the arteries. If from any cause — surgical ligation 
of an artery, pressure upon it by effusions or new growths, degeneration 
or affections of the arterial walls, the presence of an embolus or throm- 
bus (Chapter V.) — the flow of blood to a part is arrested, the nutritive 
supply ceases and the cells dependent upon that vessel perish. If the 
part receive a collateral arterial supply, the cells may retain their 
vitality, although if this supply be inadequate they are in danger of 
degeneration and atrophy. This will explain the greater relative fre- 
quency of extensive necrosis of the lower jaw, as compared with necro- 
sis affecting the upper jaw, the lower jaw being supplied mainly by one 

1 Green. 



NECROSIS. 67 

large arterial trunk, while in the upper jaw there is a freely anastomos- 
ing circulation. 

2d. Obstruction of the veins. If the entire venous outlet of a part 
be obstructed, there is not that removal of waste-products necessary to 
the life of cells ; moreover, access of nutritive material is prevented 
and the parts die. 

3d. Obstruction of the capillaries. Complete obstruction of the 
capillary supply to a part is followed necessarily by a cessation of nutri- 
tion in the part ; consequently necrosis results. For example, when an 
inflammatory effusion occurs between the surface of a bone and the peri- 
osteum, the capillaries are torn from their attachment ; and if the condi- 
tion be prolonged, necrosis of the underlying bone results. When the 
effusion occurs outside the periosteum its pressure may cause occlusion 
of the capillaries of the part. The interference with the nutritive supply 
may be due to a lack of force with which the blood is propelled, owing 
to insufficient action of the heart. Necrosis is not infrequently due to 
the violence and continuance of the inflammatory process in a part. 
Coagulation of the blood in the capillaries of a part occludes the circu- 
lation and death results. 

Class II. — Destruction of the vital activities of cells may be caused 
by any of the physical forces or by the action of chemical agents, 
including among the latter the poisonous substances formed through 
the action of bacteria. 

Injuries, blows, excessive heat or cold, the passage of powerful elec- 
tric currents, are all influences which directly injure or permanently 
destroy vital activities of cells. The application of chemical agents 
which so act upon cell-substance as to change its character produces 
necrosis. While this is particularly true of such substances as powerful 
acids and alkalies, which immediately destroy cell-integrity, it is also 
true of milder agents acting for longer periods. Certain poisons, par- 
ticularly those of bacterial origin, paralyze the vital activities of cells 
and necrosis results. 

The occurrence or non-occurrence or the liability to necrosis will 
largely depend upon the degree of vital energy of cells prior to the 
action of the active causes of necrosis. Parts debilitated from any 
cause are more liable to necrosis than those which have suffered no 
debility. A part chronically ill-nourished subjected to the causes pro- 
ducing degenerations is liable to suffer necrotic changes, for the several 
degenerations and atrophy, as shown in Fig. 22, are but successive 
stages leading to necrosis. 

When a tissue undergoes death as the result of the infliction of an 
injury the process is called necrosis per se, to distinguish it from the 



68 DISTURBANCES OF NUTRITION. 

form of death which occurs in a descending scale, which process is 
called necrobiosis. 

A necrosed part acts as an irritant to the tissues about it, inaugurat- 
ing an inflammatory reaction which marks off the dead from the living 
parts. The dead part is sequestred, and hence is called a sequestrum. 

Coagulation-necrosis. — When a dead tissue contains coagulable 
material and the necessary ferments (Chapter V.) the parts undergo 
coagulation. The cells and parts about become solidified ; the cells 
lose their nuclei and do not stain as usual. 

Liquefaction-necrosis. — When the necrosed parts are saturated 
with lymph the dead part breaks down and liquefies. 

Dry Gangrene. — When parts have died as the result of stoppage of 
circulation and the access of fluids is prevented, the dead part may 
undergo a species of mummification. 

Moist Gangrene. — When the organisms of putrefactive fermenta- 
tion gain access to a necrotic part they break down the dead tissues, 
with the formation of products described in Chapter III. The forma- 
tion of such gases as hydrogen sulfid, H 2 S, hydrogen phosphid, PH 3 , 
and ammonium sulfid, (NH 4 ) 2 S, gives the offensive odor to gangrenous 
parts. The amount of water necessary for the development of putre- 
factive organisms is not present in dry gangrene, hence putrefactive 
decomposition is absent or long delayed in this condition. 



CHAPTER V. 

DISTURBANCES OF THE VASCULAR SYSTEM. 

Ever since the physical nature of the circulatory apparatus was 
pointed out by William Harvey in 1628, disturbance of the equilibrium 
of the circulation has been held to have a close relationship with the 
process of nutrition. The sum and substance of contemporary view of 
this matter is that an increase in the flow of blood to a part means an 
increase of nutritive material in the part ; that is, increased circulation 
means hypernutrition. We shall see, however, that this belief can only 
receive qualified acceptance in the light of the latest views of this 
branch of physiology. A decrease in the supply to a part is followed 
by a diminution of nutritive material, and, as a consequence, hyponu- 
trition prevails. This distinction at once divides local disturbances of 
the circulation into two groups, viz., hypersemia, a condition in which 
there is an excess of blood in a part ; and anaemia, a condition in which 
there is a deficiency of blood in a part. In this division, however, the 
latter term is used inaccurately, for anaemia has come to be applied to 
those conditions in which there is a deficiency of red corpuscles in the 
blood, or to those conditions consequent upon hemorrhage, in which the 
general volume of the blood is lessened in amount. The corresponding 
term, indicating an excess in the volume of the circulatory fluids, is 
plethora. The word ischaemia, from the Greek ischo, I stop, is used to 
express the condition opposite to that of hypersemia. 

Condition of the Blood. 

There are two elements which enter into the discussion of the sub- 
ject of the relationship existing between nutrition and circulation, the 
first being the composition of the blood, and, secondly, its mode of dis- 
tribution — its equable supply to the several tissues and organs of the 
body. The first is a factor of prime importance, irrespective of the 
second, for abnormalities in the composition of the blood, the vehicle 
for nutritive material, and of what is of almost equal importance, 
the waste-products formed in the body, are inevitable precursors of 
disturbances of the normal nutrition of tissues — L c, are productive of 
disease. 

The first essential to the proper functionating of the great chemical 

69 



70 DISTURBANCES OF THE VASCULAR SYSTEM. 

laboratory, the human body, is that it shall receive material which will 
enable it to continue its great variety of chemical operations. The first 
of these materials, in point of importance, is oxygen ; for, as pointed 
out by the physiologist, vital action is largely dependent upon the pro- 
cess of oxidation. 

In the absence of oxygen the protoplasm of cells, no matter how 
differentiated, whether a neuron of the brain, a parenchymatous cell of 
the liver, an epithelial cell of the kidney, or the odontoblast of a dental 
pulp, cannot be the seat of chemical reactions and reductions which 
transform nutritive matter into protoplasm, or which reduce the waste- 
products of cellular activity to substances Avhich may be removed from 
the cell. Oxygen, therefore, is essential, not only to the reconstructive 
action, constructive metamorphosis, but also to the removal of waste- 
products, which, if remaining unoxidized, literally poison the protoplasm 
with which they remain in contact. 

Changes in the Composition of the Blood. — The first factor to be 
studied, therefore, in connection with the composition of the blood is its 
oxygen capacity — in short, the number of its red corpuscles. It is usu- 
ally stated that the average number of red corpuscles in human blood is 
5,000,000 in a cubic millimetre. 1 This proportion is temporarily altered 
by divers influences, so that a deficiency of red corpuscles is only spoken 
of when the deficiency is persistent. When the proportion is lessened 
the condition is spoken of as oligocythemia (Greek ollgos, few). The 
special constituent of the corpuscle with which oxygen-carrying is asso- 
ciated is haemoglobin, chemically an albuminate of iron, Avhich holds 
oxygen with a light affinity which carbon dioxid overcomes, and displaces 
the oxygen. If haemoglobin be deficient in amount, or if there be such 
a pulmonary condition that a free interchange between the blood in the 
capillaries of the lungs and the air in the acini is, interfered Avith, it is e\'i- 
dent that the supply of oxygen to the tissues will be deficient, and a con- 
dition of suboxidation will exist throughout the body, nutrition will be 
imperfect, and waste-products of incomplete metabolism be formed, with 
a tendency to their retention. Arterial blood containing those substances 
fitted for nutrition becomes unfitted for this office if the processes of 
digestion, absorption, and glandular functions, particularly those of the 
liver, do not properly transform food-stuffs into substances fitted for the 
proper performance of cell-function. Those miniature chemical labora- 
tories, living-cells, require for their special chemistry, substances elabo- 
rated by the great laboratories of the digestive system. If these sub- 
stances are not formed, the cells throughout the body receiA T e material 
unfit for their purposes. The peculiar chemistry of the seA T eral organs 
of the body will modifiy the substances contained in, particularly, the 

1 Foster's Physiology, 5th ed. 



COAGULATION OF THE BLOOD. 71 

venous blood of any region, so that the composition of the blood varies 
according to the organ in which it is found. In general terms, arterial 
blood contains the nutritive materials of the body, and the veins the 
waste-products ; to this rule, however, there are marked exceptions ; for 
example, the blood of the renal artery contains waste-matters (urea, 
etc.) to be eliminated, and the blood in the hepatic veins contains the 
food-substances which have been prepared by the liver. 

If, owing to continued faulty physiology, the quality of the blood be 
altered, either by not receiving properly elaborated food-materials or from 
the presence of an undue amount of substances which should be removed 
as waste-products, the nutrition of organs suffers, and there is inaug- 
urated the series of disturbances described in Chapter IV. Circulating 
in the body the waste-products of tissue-metabolism, if present in undue 
amount, act as irritating or paralyzing agencies upon the vital activities 
of cells, particularly upon cells whose activities are below normal, hence 
they are productive of degenerations. Urea and uric acid are marked ex- 
amples of such irritants. If the elimination of urea be checked, owing to 
disease of the kidneys, the soluble urea circulating in the blood-current 
acts as a poison to the organs of the body, and evidences of widespread func- 
tional disturbance make their appearance. Uric acid in the form of solu- 
ble urates of sodium, which should be eliminated by the kidneys, if 
retained in undue amount, owing to kidney-disease, is precipitated in 
regions having a sluggish circulation, where the vitality of the cells has 
been diminished or degenerations are in progress. It, in its turn, may 
act as an irritant in parts in which it is deposited. 

Substances formed in the intestinal canal as the result of faulty 
intestinal digestion, and poisons developed there through the action of 
bacteria, may be absorbed, and if that destroyer of poisons, the liver, 1 
fails to neutralize them, they gain entrance to the general circulation 
and act as poisons (see Septicaemia and Pyaemia). 

Coagulation of the Blood. 

The blood contains a substance, probably a globulin, out of which 
fibrin is formed ; hence it is termed fibrinogen. It is permanently solu- 
ble in the alkaline blood-serum under normal conditions ; but when 
from any cause injury or degeneration of white blood-corpuscles occurs, 
substances, called ferments, are set free from the corpuscles, which 
in the presence of calcium salts (present in the blood as phosphates 
and carbonates) combine with fibrinogen to form a new compound, 
whose solubility is altered, and a new and solid substance makes its 
appearance — fibrin. This reaction occurs in blood removed from the 
body, constituting what is called the coagulation of blood. When 
1 Brunton, Pharmacology and Therapeutics, 3d ed. 



72 



DISTURBANCES OF THE VASCULAR SYSTEM. 



Fig. 34. 



blood is drawn in a vessel, after a period it is noted that it changes 
from a fluid to a jelly-like mass, red in color. The conditions under 
which the blood is placed cause partial disintegration of leucocytes, 
paraglobulin and ferments are set free, which, combining with the 
fibrinogen of the blood, form fibrin ; the corpuscular elements become 
entangled in the meshes of the fibrin. 1 Under some conditions this 
process occurs in living bloodvessels. When from any cause the endo- 
thelial cells lining bloodvessels have suffered injury, whether by me- 
chanical injury or the presence of substances which cause irritation, 
an accumulation of leucocytes occurs in the locality and the reaction 
called coagulation occurs. The process seems to be determined by a 
slowing of the blood-current in the affected vessel, and it is extremely 
probable that changes in the chemical composition of the blood play an 
important part. 

Thrombus. — When a coagulum forms in a vessel it is known as a 
thrombus (Greek thrombos, a clot of blood). It may form in the vessels 
or in the heart ; may remain where it has formed, or be transported 
to other parts, forming what is called an embolus (Greek embolon, a 
piston). Whatever its situation, the significance of a thrombus or embo- 
lus is mechanical interference with the circu- 
lation, and its effects are governed by the 
extent to which the blood-supply of a part is 
occluded. If the embolus be formed of tumor- 
cells or of bacteria which have gained entrance 
to the circulation, secondary disease-processes 
are set up. Remaining in the situations in 
which they were formed, thrombi undergo de- 
generative changes. In one of the typical 
situations, in varicose vessels, when the vas- 
cular current is much slowed, thrombi fre- 
quently form and undergo calcareous degen- 
eration (which see), forming what are called 
phleboliths (vein-stones). If the occluded 
vessel be what is called a terminal artery — 
that is, an artery whose branches spread like 
those of a tree, without anastomosis — the area 
to which it is distributed undergoes degenera- 
tion and death. The backward pressure from 
the veins upon the blood-current of the capillaries causes rupture 
of the latter, and an extravasation of blood into the Avedge-shaped 
(Fig. 34) area occurs, forming what is called a hemorrhagic infarct. 

1 For extended description of this process see Foster's Physiology and Landois' 
Physiology. 




a v 

Diagram of a hemorrhagic in- 
farct : a, artery obliterated by 
an embolus (e) ; v, vein filled 
with a secondary thrombus 
{th) ; 1, centre of infarct, which 
is becoming disintegrated ; 2, 
area of extravasation ; 3, area 
of collateral hyperemia. (O. 
Weber.) 



PLATE I. 



Fig. 1, 



Fig. 2. 



if 



fc 



« 



* 




9aS& N 

-~ . o 






o 




.* 



O CO 















Severe Anaemia with 
Leueoeytosis. 

Dry preparation. Fixed with picric acid. 
Stained with hsematoxylin Bohmer, x 300. 

Red corpuscles few, almost colorless, varying 
in size, show poikilocytosis ; two nucleated reds 
(normoblasts). The increase in the white cells 
seen to be in the polynuclear elements (Rieder's 
''Alias der Kllnischen Mikroskopie des B lutes.") 



Splenie-myelogenie Leukaemia. 

Eosin-hsematoxylin, x 300. Red corpuscles 
rosy-red, of nearly uniform size, round. To the 
left a normoblast with eccentrically placed nucleus. 
Many large mononuclear leucocytes (myelocytes) 
and three eosinophiles seen. (Rieder.) 



Fig. 3. 



Fig. 4. 












Splenie-myelogenie Leukaemia. 

Same case. Eosin-haematoxylin, x 1100. One 
normoblast, one polynuclear leucocyte, one 
myelocyte, two eosinophiles. The neutrophilic 
granules of the polynuclear leucocyte and of the 
myelocyte do not show with this stain. The large 
mononuclear eosinophile above is believed to be 
also a myelocyte (Markzelle), the smaller one be- 
low, an eosinophile such as can be found in nor- 
mal blood. (Rieder.) 



Myelocyte, normoblast, 
megaloblast. 

Triple stain. G, myelocyte showing neutro- 
philic granules ; H, normoblast, both from a case 
of splenic myelogenic leukaemia ; I, large nu- 
cleated red corpucle (megaloblast) from a case of 
pernicious anaemia. (Osier.) 



PHAGOCYTES OF THE BLOOD. 



73 



The death of the dental pulp is no doubt frequently due to this 
process. 

Thrombi formed in veins may find their way, via larger veins (Fig. 
35), into the heart, and thence be driven into the branches of the pul- 




Fig. 36. 




A thrombus in the saphenous vein, showing 
the projection of the conical end of the 
thrombus into the femoral vessel : S, 
saphenous vein ; T, thrombus ; C, conical 
end projecting into femoral vein. At v, v, 
opposite the valves, the thrombus is soft- 
ened. (Virchow.) 



Embolus impacted at the bifurcation of 
a branch of the pulmonary artery, 
showing the formation of thrombi be- 
hind and in front of it, and the exten- 
sion of these as far as the entrance of 
the next collateral vessels : E, embo- 
lus; t, V ' , secondary thrombi. (Virchow.) 



monary artery. Thrombi formed upon the arterial side, if detached, 
are driven along the artery to a vessel or junction of vessels refusing 
passage to them, when the results of thrombus are suddenly set up 
(Fig. 36). 

Phagocytes of the Blood. 

The white corpuscles, the leucocytes of the blood, are of great 
clinical importance. Several varieties of the white corpuscles are 
to be recognized: 1 1. Lymphocytes, derived from the lymphoid tis- 
sues of the body, forming 20 to 30 per cent, of all of the leucocytes 
of the blood ; they are probably immature leucocytes. 2. Large 
leucocytes having a single nucleus, which take up acid eosin, stain 
readily (eosinophiles), forming 2 to 3 per cent, of leucocytes of blood. 
3. Smaller leucocytes containing several nuclei, Avhich stain only with 
a mixture of basic and acid dyes, and hence called neutrophiles ; 
they form two-thirds the entire number of leucocytes. 4. Transi- 
tional forms, constituting about 3 per cent. ; they are between the 
mononuclear and polynuclear forms. 5. Eosinophile cells, size of No. 
3 nuclei, variable ; they constitute from 2 to 4 per cent, of leucocvtes. 
(Plate I.) 

Under some conditions, notably during diseases in which suppurn- 
1 Park's Surgery, vol. i., and Metchnikoff's Lectures. 



74 



DISTURBANCES OF THE VASCULAR SYSTEM. 



tion occurs, there is a marked increase in the poly nucleated leucocytes. 
This fact has been applied as a diagnostic sign of the existence of sup- 
puration ; l if leukocytosis be present during the course of surgical dis- 
eases, suppuration and retention of pus are to be suspected. The large 
mononuclear and the polynuclear forms of leucocytes have pronounced 
phagocytic activity ; it is held that the reason for their increase is the 
presence in some part of the body of substances acting as tissue-irri- 
tants. These cells are most active in disposing of invading bacteria, 
and are present in great numbers in areas of inflammation. 

Disturbances of the Vascular Mechanism. 

As stated, disturbances in the equilibrium of the circulation may be 
conveniently grouped under two heads, a hypo- and a hyper- group, or 
conditions of ischsemia and conditions of hyperemia. These may be 
again divided according to the extent of the disturbance, ranging, on 
the one hand, from a slight decrease in the circulation of a part, to its 
entire occlusion or stoppage, on the other hand : the range extends 
from a slight increase of circulation to an entire paralysis of vessel- 
walls. In either event the tissues depending upon the supply of blood 
through the affected vessels are adversely affected, it may be to the 
extent of their death. 

The grades and effects of both types of vascular disturbances are 
graphically represented in Fig. 37. 









Fig. 37. 
Health 






Stimulation / 


\ Atony 


3 


Increased Function/ 
Hyperaemia / 






\ Lessened Function 

\ & 
\ ° 

\ Ischaemia ^ 




Hyperplasia J 
Inflammation \ 






\ Atrophy S 

\ a 

\ Occlusion 




Degeneration \ 

Stagnation |j 


Necrosis 






Necrosis 


1 Degeneration 
| Stagnation 



Death 



The cause of the lessened blood-supply to an organ may be at any 

portion of the circulatory apparatus— the heart, the arteries, capillaries, 

or veins. The heart itself, through degenerative changes in its muscle, as 

in fatty degeneration of the organ, may propel the blood with insufficient 

1 Cabot, Boston Med. and Surg. Journ., March 22, 1894. 



DISTURBANCES OF THE VASCULAR MECHANISM. 75 

force. The presence of effusions in the pericardium may lessen the 
force of the heart's contraction. If an obstruction clue to disease of the 
valves of the heart causes a narrowing of any of the orifices of the 
heart, the blood- pressure in the arteries falls, hence circulation is less 
active. If, as the consequence of disease of the valves of the heart, 
these structures do not entirely close their respective orifices, there is a 
backward flow of blood into the corresponding heart-cavity and the 
pressure in the vessels is lessened. Owing to degenerations of the walls 
of the vessels, mainly the arteries, they may lose their elasticity, and 
hence this element of equalizing blood-pressure fails and local circula- 
tion becomes disordered. The presence of a thrombus or embolus may 
mechanically impede the flow of blood to or from a part. 

In any of these cases the tissues of the body suffer a disturbance of 
their blood-supply and are in danger of the hyponutritional changes 
described in Chapter IV. These changes in the vascular mechanism 
frequently occur at a time of life when the vitality of tissues is on the 
Avane, so that degenerative changes are common. The changes in the 
vessels may be localized, in which case the nutritional effects are in 
correspondence. 

Hypersemia. — The term hyperemia has reference to a localized con- 
dition. It means an increase in the activity of the circulation of a part. 
There are, however, conditions in which the entire vascular system ap- 
pears to be overfull ; the patient is said to be plethoric. Individuals who 
present this appearance are of two classes : those in which the vessels 
appear to be overfull and the circulation very active, or sthenic plethora, 
and those in which overfulness of vessels is associated Avith a sluggish 
circulation, or asthenic plethora. In sthenic plethora the general vital 
processes are active, and inflammations are quickly lighted up and run 
an active, but not dangerous course ; the condition exhibits the phenom- 
ena of overfull arteries. On the contrary, in asthenic plethora, while 
the vessels are overfull, the circulation is sluggish and vital processes 
appear to be in correspondence. It is these two types which probably 
gave origin to the names of two of the basal temperaments, the san- 
guineous and lymphatic. Both conditions certainly exercise a govern- 
ing influence in pathogenesis in the classes of clinical histories, prog- 
nosis, and treatment of diseases to which such persons fall victims. 

The Pulse. — These and other conditions of the circulatory apparatus, 
are noted by studying the pulse — i. e., the force, frequency, and regularity 
with which the blood is driven through the vessels. A knowledge of the 
general condition of the circulatory apparatus is gained by noting, first, 
the condition of the heart-beat. In a normal condition of the circula- 
tory apparatus the heart-pulsations number from 70 to 80 a minute, 
accompanied by two distinct sounds with an interval between them, and 



76 DISTURBANCES OF THE VASCULAR SYSTEM. 

the sensation, when a superficial artery is pressed upon, of a quickly 
rising and quickly subsiding wave and with a moderate degree of ten- 
sion, the artery filling like an elastic tube. Any variation in any of 
these particulars indicates necessarily a disturbance in the vascular mech- 
anism. If the heart-sound is feeble, it indicates lack of power, the 
pulse-wave, on measurement with a sphygmograph, showing a short 
wave. If the contraction be slow, below 70, it is noted in the pulse ; if 
both slow and weak, the pulse lacks tension, is compressible. If in- 
stead of the normal heart-sound a murmur or murmurs are heard, dis- 
turbance of the valves of the heart is indicated, and the tension of the 
arteries is below normal, the pulse-wave is disordered. In case of nar- 
rowing of the entrance of the aorta (aortic stenosis) the wave rises 
quickly and falls suddenly. In case the mitral valve fails to completely 
separate the auricle and ventricle in contraction, the wave is small and 
irregular. If the heart-sounds are pronounced, it indicates that a full 
volume of blood is being driven into the aorta. 

Turning from an examination of the heart to a study of the arteries 
themselves, valuable indications as to the condition of the circulation 
are obtainable. It is to be recalled that the arteries are kept in a state 
of moderate contraction through the influence of the vasomotor nerves, 
probably by a balance between the influence of vasoconstrictor and vaso- 
dilator nerves. This point is, however, not well made out ; it is not 
clearly determined whether dilatation occurs as the result of stimulation 
of one class of nerves, and contraction to stimulation of another class, or 
whether contraction is due to a set of nerves which, when dilatation oc- 
curs, are inactive. The latter hypothesis would imply that when vaso- 
motor paralysis occurs the vessels are passively dilated to more than 
their normal size and are inelastic, this agreeing with observed clinical 
phenomena. The arteries are normally in a state of tension, so that 
when the blood-column contained in them is pressed upon by a mass of 
blood ejected from the left ventricle the column is impelled forward, 
which, meeting the resistance of the blood in the smaller vessels beyond 
the arterial trunk, causes an elastic distention of the artery. 

The tension of the artery may be raised or lowered, according as the 
vessel is in more than normal or less than normal contraction. When 
the artery is in extreme contraction owing to overstimulation of the 
vasoconstrictor nerves, or from irritation of the vasomotor centre, the 
pulse is found to be small and hard ; hard because of the tenseness of 
the arterial wall, and small for the same reason— the blood-column is 
unable to dilate the tense vessels. 1 This is the condition found in angina 
pectoris (neuralgia of the heart), in which the heart labors to overcome 
the spasmodic contraction and may suffer paralysis in its efforts. The 

1 Hare, Practical Diagnosis, 1896. 



ARTERIAL HYPEREMIA. 77 

administration of the nitrites, amyl nitrite or trinitrin, paralyzes the 
nerve-centre, dilatation of the vessels occurs, and the heart is relieved. 1 
Changes in the arterial wall due to disease of the coats may bring about 
a condition of heightened tension. 

The conditions of the pulse are referred to as frequent or infrequent, 
corresponding with the heart-beat ; as regular or irregular, corresponding 
with the heart-beat. The pulse may be full or small ; full, relating to 
the volume and the extent of arterial expansion. Fulness is usually 
associated with strength of pulse, although not always. A small pulse 
is usually a Aveak pulse ; but if the artery be much contracted, it may 
be both small and strong. The pulse may be soft or hard ; hard in 
increased tension (see above) ; soft Avith diminished tension and dimin- 
ished heart-power. 2 A hard, full, frequent pulse occurs in active in- 
flammations. A hard pulse, full or small, bounding or not, if uncon- 
nected with acute symptoms, leads to suspicion of cardiac disease or 
an affection of the artery itself. A very frequent pulse, but feeble and 
compressible, is the pulse of marked debility, of prostration, of collapse. 

It is by these several signs that the mode of distribution of blood 
throughout the body is gauged, although not positi\ T ely determined, for 
disturbances in the circulation of a part may occur, and only be deter- 
mined by a symptomatology referable to the part. 

In the beginning of this chapter it was stated that there are two 
recognized types of hyperemia : one in which the distention of A^essels 
was upon the arterial, the other in which it is upon the venous side of 
the circulation. The two types differ as to causes, phenomena, and 
effects, and as to the indicated treatment for each. 

Arterial Hyperemia. 

Arterial or active hyperemia is an increase in the amount of blood 
in the dilated arteries of a part. 

Causes. — The direct cause of hyperemia of a part is a lessened arte- 
rial resistance ; the tension of the arterial Avails is lessened by a stimula- 
tion of the vasodilator nen 7 es or by a sedation of the \ T asoconstrictor 
nerA r es, the former being the more probable explanation. It expresses the 
reaction which occurs as the consequence of the presence of an irritant. 
Alternate rise and fall in arterial tension occur in health ; it is only 
when the condition is prolonged that it becomes pathological. If the 
sensory nerves of a part are stimulated or irritated, hyperemia of the 
irritated parts occurs as a reflex. If the surface of the body be irritated 
at certain points, as by the application of heat, it appears that in some 
cases hyperemia may be induced in deeper-seated organs as a reflex. 3 

1 Brunton's Pharmacology. 2 DaCosta, Medical Diagnosis. 

3 Green's Pathology and Morbid Anatomy. 



78 BISTUBBANCES OF THE VASCULAR SYSTEM. 

Hyperemia may be compensatory, as when, through the removal of one 
of a pair of organs having the same function, an increased blood-supply 
is present, and increased work is performed by the remaining organ. 

Symptoms. — The symptoms accompanying hypersemia of a part are 
such as would be directly surmised as soon as the condition was defined. 
There are increased redness, an elevation of temperature, and more or 
less throbbing, and in some cases some degree of throbbing pain. 1 

Pathology. — The arteries are dilated : there is an increased flow of 
blood through them and also to them through their own nutritive 
arteries ; the pressure in the veins rises, but exudation does not appear 
to increase in all cases, as there is no increase of lymph-pressure, although 
in marked cases oedema may occur. Two types of arterial hypersemia 
appear to exist : one due to excitation of the vasodilator fibres, a neuro- 
tonic congestion ; the other, a neuroparalytic congestion, caused by 
paralysis or sedation of the vasoconstrictor fibres (Recklinghausen). 

Results of Active Hypersemia. — The nutrition of the part is in- 
creased ; there is in the less pronounced cases an increase in the func- 
tional activity of the part ; secretion is increased ; the vital activities 
are elevated. In more pronounced cases, where the symptoms of red- 
ness, heat, swelling, and throbbing pain occur, the function of the part 
is disturbed. Many of the cases formerly included among the mild 
inflammations are now placed under the head of active hypersemia. 

The character and composition of the exudates differ widely in the 
two conditions : 

Hypercemie Exudates. Inflammatory Exudates. 

Poor in albumin. Rich in albumin. 

Rarely coagulate in tissue. Usually coagulate in tissue. 

Contain few cells. Contain numerous cells. 

Low specific gravity. High specific gravity. 

Contain no peptone. Contain peptone. 2 

The lesser forms of hypersemia if continued may lead to hypertrophy 
of the affected organ and of the vessels. In the more marked forms the 
changes induced approach the degenerations. 

Treatment. — The principle of treatment is to remove the cause and 
procure surgical rest. The source of the irritation is to be sought out 
and removed when possible ; as a rule, the symptoms then promptly 
subside. It may be that the conditions existing require treatment irre- 
spective of the cause, which may not be determined or be absent, the 
vessels being dilated as the effect of a previously acting cause. The 
principle of treatment is the reduction of the dilated vessels. This is 
attempted at times through the use of drugs ; for example, the adminis- 

1 Warren, Surgical Pathology and Therapeutics. 2 Park's Surgery, vol. i., p. 25. 



VENOUS HYPEREMIA. 79 

tration of ergot, which, by stimulating the vasoconstrictor system, les- 
sens the calibre of the dilated vessels. The antagonist of ergot, aconite, 
has also been used. By paralyzing the vasoconstrictor system and quiet- 
ing the usually overacting heart-muscle it lessens the amount of blood 
flowing to a part in a given time. 

The usual method of inducing contraction is by local applications of 
dry cold, which cause contraction of the arteries. 

The principle of derivation is also employed : by local bloodletting, 
by incision, wet cups, or leeches applied beyond the margins of the 
hypersemic area, the engorged vessels are unloaded. Frequently the 
administration of a diaphoretic or diuretic, by diverting the blood-cur- 
rent, causes a lessened flow to the affected area. The administration of 
a saline cathartic lessens the fluid volume of the blood, and, conjoined 
with local measures, reduces the engorged vessels. 

What is known as counterirritation is a common means of treatment. 
An irritant, such as a mustard-plaster or a blister, applied at a distance 
from the affected part, induces a flow of blood to the point of applica- 
tion and lessens the amount of blood in other parts. The volume of 
the blood being in definite amount, if an excess exist in any part, a 
deficiency will be found in other parts. 

Sedative astringents (the liquor plumbi subacetatis) are used to con- 
tract dilated vessels. Other astringents (see Pharmacology) induce dila- 
tation of vessels, and so are contraindicated. 

Perhaps the most effective measure is local bloodletting, and in the 
more continued cases the repeated application of cold. 

Venous Hyperemia. 

By venous hyperemia is meant an excess of blood in the dilated 
veins of a part. 

Causes. — Its causes are mechanical interference with the return of 
the blood to the heart. 

Symptoms. — The symptoms of this condition are blueness (instead 
of redness), a lessened temperature, and swelling. 

Pathology and Morbid Anatomy. — The veins are dilated, the cur- 
rent is slowed, and intravenous pressure is increased, in consequence of 
which watery exudations occur in the parts about them. The deficiency 
of arterial and the excess of venous blood, with interference with its 
return to the heart, are followed by deficient supply of oxygen, a lessened 
food-supply, and the retention of waste-products : the effects are in 
correspondence, vital processes are lessened, secretion is diminished, 
there is less oxidation, and hence less heat is produced and less work 
is done. The functional activity of the parts suffers, and degenerations, 
atrophy, or necrosis may occur. 



80 DISTURBANCES OF THE VASCULAR SYSTEM. 

Treatment. — The principle of treatment is the removal of the me- 
chanical obstruction to the return of the blood and mechanical sup- 
port of the engorged vessels. This latter is accomplished by means 
of elastic bandages, and in situations in which these cannot be used, 
astringents may be employed. The part is elevated when possible, to 
aid in the return of the blood to the heart. 

The succeeding type of tissue and vascular reaction toward an irri- 
tant — inflammation — must be treated as a process sui generis, although 
exhibiting many features of pronounced arterial hyperemia. 

Inflammation. 

There is no condition described in pathology which has received such 
a variety of definitions as that of inflammation. A general consensus 
of opinion places inflammation in the category of the conservative pro- 
cesses, viewing it as essentially Nature's means of ridding the tissues 
of an intruding substance — an irritant. 

As a general description, there is perhaps no better definition 
than that of Sanderson : l " Inflammation is the succession of changes 
which occurs in a living tissue as the result of some kind of injury, 
provided that this injury be insufficient to immediately destroy its 
vitality." 

A definition which expresses the pathological features found in this 
condition better than any other is that of Ziegler : 2 "It is essen- 
tially a local tissue-degeneration combined with pathological exudations 
from the bloodvessels, followed sooner or later by tissue-proliferation, 
leading to regeneration or hypertrophy." 

It has been suggested 3 that the term inflammation be dropped from 
use, as it includes so many factors which are variable in occurrence as 
to give the word but indefinite meaning. 

Causes. — The causes are injuries of any description which induce a 
higher degree of irritation than those producing active hyperemia. The 
sources of these irritations or injury are many and varied. They may 
be included under the heads of mechanical violence, the action of 
physical forces, the action of chemical substances, and the action of 
parasites and their products. Any one or more of these influences 
acting upon a vital part may induce the inflammatory process. 

The causes may be extrinsic or intrinsic ; while most of them act 
from the exterior of the body, substances formed in the body, such 
as uric acid, are sufficient irritants at times. 

Inflammations which are caused by the action of physical or chemi- 
cal agencies are usually termed simple ; those arising through the in- 

1 Holmes' System of Surgery, vol. i. a General Pathology, 1895. 

3 Thoma, General Pathology, vol. i. 



INFLAMMATION. 



81 



fluence of vegetable parasites or their products are named infective in- 
flammations. 

Pathology. — Inflammation may he fitly regarded as one stage of a 
series of nutritive disorders which begins in stimulation and ends in 
necrosis. It is a profound disturbance of the nutritive functions of a 
part. The pathology of inflammation is studied by inducing the condi- 
tion in transparent and vascular membranes of animals, which may be 
fixed to the stage of the microscope. 

The first effect of the application of a sufficient irritant to a part is 
the quick contraction of the arteries, followed immediately by a dilata- 
tion of arteries and veins, the velocity of the current increasing ; the 
blood-pressure is at this stage apparently not marked, for there is but 

Fig. 38. 




Inflamed human omentum. The phenomena of inflammation are seen in the veins and capil- 
laries, the condition being normal at the artery (c), where b represents endothelium covering 
the trabecula (a). In the vein (d) there are many white corpuscles along the wall: some of 
these are emigrating (e) ; /, desquamated endothelium ; g, extravasated red corpuscles. (Ziegler.) 

little dilatation of the capillaries. Up to this point there is nothing ob- 
served which could not be explained by a paralysis of the vasoconstrictor 
or stimulation of the vasodilator nerves ; the process of inflammation 
proper begins when the blood-stream in the emergent veins is seen to 
be retarded and an exudation is poured out of the small veins and cap- 
illaries ; with the slowing of the current the increased blood-pressure 
causes a marked dilatation of the capillaries. An evident change may 
now be noted in the condition of the walls of the vessels. 1 The leuco- 

1 Cohnheim and Samuel. 



82 DISTURBANCES OF THE VASCULAR SYSTEM. 

cytes, which before the inception of the condition were few and scattered, 
are seen from the beginning of this process of retardation to cling and 
mass in numbers along the walls of the smallest veins, the large mononu- 
clear and the multinuclear forms particularly. Instead of the usual exu- 
date of lymph, the vessels of the area iioav pour out an abundant exudate 
rich in albumin, and soon the white corpuscles may be seen making their 
way through stomata of the veins to the intercellular spaces (Fig. 38). 
The area about the bloodvessels is soon filled with a mass of mobile 
cells. The origin of all these cells is a mooted point. It was taught 
by Virchow that they arose from the multiplication of the connec- 
tive-tissue corpuscles of the part ; and later, their origin Avas stated by 
Cohnheim to be solely from the leucocytes which had made their escape 
from the vessels. It is the belief at present that they arise mainly from 
the leucocytes at this stage of the inflammatory process. 

The diapedesis is explained by Metehnikoff as Nature's defence against 
an intruding and injurious body. When such a body, or when a source 
of marked irritation is present, the leucocytes throng to the point of 
irritation, emerge from the vessels, and attack the intruder, exercising 
their phagocytic activity against it. If the intruder is of smaller size 
than the leucocytes (as bacteria), it is enclosed by the latter, killed, and 
digested. Large bodies are attacked and surrounded en masse by leuco- 
cytes. If the phagocytic cells conquer, the acute symptoms subside and 
a series of changes occur which lead to a restoration of health. If the 
bacteria or other intruders prevail, the phagocytes succumb, die, and 
form what are called pus-corpuscles. 

The blood in the capillaries comes to a standstill, a condition of 
stasis. Coagulation of the blood, however, does not occur, as a rule ; for 
if the blood-flow be re-established, the separate red corpuscles are seen, 
one by one, to roll away from the general mass until all are in move- 
ment and stasis ceases (Thoma). The affected area becomes filled with a 
mass of indifferent cells and remnants of broken-down tissue, for it ap- 
pears that the nutritive balance of the tissue-elements of the part is 
entirely lost, and that profound degenerative changes occur in them ; it 
is believed, therefore, that the source of the cells at the height of the 
inflammatory process is from the leucocytes alone. The albuminous 
exudate, in the presence of injured leucocytes, is in fit condition to 
coagulate, and coagulation of the effusions occurs. The area of inflam- 
mation now represents virtually a mass of embryonic tissue containing 
foreign substances. The inflammation may take one of two courses : 
the inflammation may abate, and a restoration of health and regenera- 
tion of tissue in the parts take place ; or the cells of the exudation, 
together with more or less of the tissue, may die. In the former case 
the process is called resolution ; in the latter, . suppuration. 



INFLA MM A TION. 83 

It is interesting, in this connection, to review the beliefs as to the 
causative agents in inflammation. It has been demonstrated quite 
clearly that the process of suppuration occurs only in the presence of 
bacteria or their waste-products. It is held by one school of pathologists 
that true inflammation also occurs only in consequence of the presence 
of similar causes, the inference being drawn mainly from Metchnikoff's 
observations. Another school hold that inflammations are of two types 
— simple and infective. If suppuration occurs only in the presence 
of bacteria or their products, then pus-formation cannot be a result of 
what are termed simple inflammations. We are compelled, therefore, 
either to believe that the evidence as to the invariable association of pus 
and bacteria is insufficient and faulty, or else hold that all inflammations 
are bacterial. The evidence as it exists divides inflammations into two 
classes : first, those certainly infective ; secondly, those not certainly 
infective. 

Symptoms. — The classical symptoms of inflammation are rubor, 
tumor, dolor, color, etfuncbio laesa, or redness, swelling, pain, heat, with 
disturbance of function. The general symptoms are usually an increased 
heart-action, some elevation of the temperature of the body, and dis- 
turbances in secretions. The redness is due to an increased amount of 
blood in the part, the color being deeper in the centre of the inflamma- 
tory area. The swelling is due to the exudation ; the hardness of the 
swelling being due to coagulation of the effusion. The pain is the result 
of the pressure of the effusion upon sensory nerve-terminals ; it is fre- 
quently throbbing, in correspondence with the heart-beat. The heat is 
owing to the greater amount of arterial blood carried to the part ; experi- 
ments to show that there is an increased generation of heat in an inflamed 
part have resulted negatively. 1 The function of the part is disturbed from 
mechanical and vital reasons ; the presence of the exudation itself tends 
to disturb functional activity, but there is, beyond doubt, in inflam- 
mation a profound disturbance of the nutritive balance in the tissues. 
Any one or more of these symptoms, except disturbance of function, 
which is a truly cardinal symptom, may be absent in some anatomical 
situations. 

Seat of Inflammation. — Virchow divided inflammations into par- 
enchymatous and interstitial, according to the portion of the organ 
attacked. Parenchymatous, those in which the functional cells of a part 
were affected ; interstitial, those in which the connective tissue was 
affected. True inflammation occurs only in the perivascular connective 
tissue, so that it is always interstitial. It has been suggested that the 
term parenchymatous inflammation be abandoned, but there is no other 
term at present which expresses the condition — a profound disturbance 
1 Warren's Surgical Pathology and Therapeutics, 1895. 



84 



DISTURBANCES OF THE VASCULAR SYSTEM. 



of the vascular supply underlying these cells, accompanied by a granular 
degeneration of the cells and their death. 

When the effusion contains a small amount of albumin and cor- 
puscles the condition is called a serous inflammation. 

In effusions largely corpuscular coagulation occurs, and a fibrinous 
inflammation is spoken of. 

If the effusions and corpuscles make their appearance upon the sur- 
face of a mucous membrane, and there is more or less swelling and 
desquamation of the epithelial cells, the condition is termed a catarrhal 
inflammation (Fig. 39). 

Fig. 39. 




Acute bronchial catarrh : passage of leucocytes through the epithelium of the bronchus between 

the ciliated cells, x 700. (Thoma.) 



Treatment. — The cardinal principle in the treatment of inflamma- 
tion is the removal of its cause. As inflammation is Nature's means of 
ridding herself of an irritant, the removal of the irritant by the operator 
is the most efficient aid in the process. As the majority of inflamma- 
tions are certainly due to the action of bacteria, the removal of 
bacteria and their products is the principal aim of treatment (see 
Chapter VI.). 

Aside from the consideration of removing the cause, the treatment 
of inflammation is directed to modifying or removing the several condi- 
tions which give rise to the symptoms. The tissues are overloaded with 



REGENERATION OF TISSUES. 85 

exudation which the lymphatic vessels cannot remove ; the bloodvessels 
are distended by an increased amount of blood, whose exit is blocked, 
but which is receiving additions with each pulse-beat, increasing the 
pain, swelling and heat. The indication is clear — relieve the stagna- 
tion. The direct causative factor of the stagnation is the vascular supply ; 
if the blood can be made to flow freely along the clogged veins, the flow 
through the capillary area will also be re-established. If less blood 
is carried to the part, there will be no additional stagnation. So long 
as the vascular congestion persists there is no possibility of removal 
of the effusion by the lymphatics. 

Nancrede found, on dividing a vein upon the distal side of an 
area of inflammation, that after a brief period the flow of blood was 
established through the inflamed area. Local bloodletting by leeches 
(Gensmer) produced even more marked effects. Drugs which stimulate 
the vasoconstrictors (ergot), and those which paralyze the constrictors 
(aconite), lessen the blood-pressure in the inflamed area, so that if 
administered in the early stages of inflammation they may modify its 
severity. If, on the contrary, they are administered after stasis occurs, 
they increase the stasis — ergot actively and aconite passively. If the 
flow of blood through the inflamed area is re-established by local blood- 
letting, after the period of stasis, then the arterial sedatives are dis- 
tinctly useful in lessening the flow of blood to the part. 1 

When, owing to vascular engorgement, throbbing pain is a promi- 
nent symptom, applications of cold are useful in lessening the calibre 
of vessels and in relieving pain. But if there be firm exudation and 
marked stasis, cold is a detriment. Heat then gives relief through 
inducing a more free flow of blood in the collateral circulation. Very 
hot applications act as do cold applications, by causing contraction of 
vessels, and may be used to abort an inflammation. 

General sedatives are at times demanded for the relief of pain. 
Morphia, used in small and continued doses, not only relieves pain, but 
causes a contraction of small vessels. 

Regeneration of Tissues. 
When the inflammatory action terminates without the formation of 
pus a series of changes is instituted which normally results in a 
reorganization of the area of degeneration. This is termed the process 
of repair. The pathological exudations cease, the vessels resume their 
normal tone, tissue which has died as the result of the inflammation is 
cast out or is absorbed (eaten by the phagocytes) and removed, and the 
exudate is absorbed by the lymphatics. The site of inflammation is 
now filled with a mass of indifferent embryonic corpuscles, consisting in 

1 Warren, Ibid. 



86 DISTURBANCES OF THE VASCULAR SYSTEM. 

Ftg. 40. 




Isolated cells from a granulating wound: a, uninuclear leucocyte; a\, multinuclear leucocyte; 
b, different shapes of uninuclear formative cells ; c, double nucleated formative cells ; C\, 
multinucleated formative cells ; d, formative cells in the process of tissue-formation ; e, com- 
pleted connective tissue. Picrocarmine preparation. X 500. (Ziegler.) 



Fig. 41. 




Development of a bloodvessel by formation of offshoots, from preparations which were taken from 
a formation of inflammatory granulations : a, b, c, d, different forms of offshoots— some solid 
(b, c), some becoming hollow (a, 6, d), some simple (a, d), some branching (b, c), some without 
nuclei (a, d), some with nuclei (6, c). Formative cells have applied themselves to the outside 
of the offshoots. (Ziegler.) 



REGENERATION OF TISSUES. 87 

part, no doubt, of embryonic cells of the several tissues destroyed by 
the inflammatory process, among which are numbers of leucocytes (Fig. 
40). It is out of this embryonic tissue that a reproduction of the several 
tissues takes place. It is to be remembered that while any of the 
several connective tissues — the tissues of mesoblastic origin — may be 
reproduced from this embryonic tissue, epithelial tissue is never repro- 
duced save from epithelium. 

The embryonic tissue soon acquires a new blood-supply (Fig. 41). 
In the endothelial cells of the walls of the capillaries about the part 
division of the cell-nucleus takes place, and by the reproductive process 

Fig. 42. 




A granulating surface : a, layer of pus ; b, granulation-tissue with loops of bloodvessels ; c, com- 
mencing development of the granulation-tissue into a fibrillated structure. X 200. Diagram- 
matic. (Rindneisch.) 



a bud grows from the capillary wall ; by repeated reproductions solid 
columns of cell-substance are formed which, joining columns from other 
capillaries, form loops, the centre of the columns becomes hollowed out, 
forming tubes which transmit blood — i. e., new capillaries are formed. 
The mass of embryonic tissue becomes thus permeated by a network of 
new capillaries (Fig. 42). The tissue in its present state is known as 
granulation-tissue. The cells of granulation-tissue are partly hyper- 
trophied tissue-cells and partly mono- and polynucleated leucocytes. 1 

1 Ziegler's General Pathology, 



88 DISTURBANCES OF THE VASCULAR SYSTEM. 

When the cells have organized and are transformed into connec- 
tive-tissue forms and arrangement, contraction takes place, and most of 
the new bloodvessels are obliterated ; the new tissue becomes pale — it is 
a cicatrix. The indifferent embryonic cells may have the function of 
forming any of the connective tissues. If cartilage is to be formed, 
chondrification takes place about the specialized cells. If bone is to be 
formed, each cell becomes an islet around which calcification proceeds. 
If epithelium have been lost, the epithelium existing undergoes prolif- 
eration, growing inward from the sides of the area denuded of epithelial 
covering, until a new epithelial surface is formed. 



CHAPTER VI. 

INFECTIVE INFLAMMATIONS: SUPPURATION, ABSCESS, 
FEVERS, SEPTICEMIA, AND PYAEMIA. 

An infective inflammation may be defined as a condition in which 
the phenomena described under the head of inflammation are caused by 
or characterized by the presence and development of pathogenic bacteria. 
In the light of MetchnikofPs studies, many pathologists maintain that 
inflammation is always an infective process ; that it is in consequence 
of the presence of bacteria that the phenomena of inflammation occur. 
This view is not entirely subscribed to, particularly by German patholo- 
gists ; but the belief is daily gaining ground among the pathologists of 
other nationalities that Metchnikoff 7 s theory, even though not meeting all 
conditions, furnishes the most satisfactory explanation of the etiology of 
inflammation ever presented. This theory is, in substance, " that the pro- 
cess of inflammation is one of the factors in organic evolution. Begin- 
ning with the amoeba, this simple organism, the analogue of the white 
blood-corpuscles has the power of englobing and digesting solid matters, 
such as bacteria, with w r hich it is brought in contact." In animals pro- 
gressively higher in the zoological scale, wandering cells of the body, 
similar to the white blood-corpuscles, exhibit this property, until in 
the mammalia, including man, Metchnikoff holds that the same cells 
have as a distinctive function the attacking and removing of foreign 
substances, pathogenic organisms included, which gain access to the 
body. As noted in discussing the subject of bacteria (see Chemotaxis), 
special properties of the invading substance may determine whether it is 
to be attacked and removed by the white blood-corpuscles, or whether it 
is avoided by these same cells. He sums up his investigations, made 
upon all classes of animals, and after reviewing the experiments of Vir- 
chow, Samuel, and Cohnheim, with the dictum that " The essential and 
primary element in typical inflammation consists in a reaction of the phago- 
cytes against a harmful agent" l 

Metchnikoff and his followers maintain that the changes which occur 
in the absence of bacteria are not characterized by the flocking and dia- 
pedesis of leucocytes ; that this latter phenomenon is, in fact, the distin- 
guishing feature of inflammation ; and that conditions following injuries 
of other kinds belong to the hyperemias. 

1 Metchnikoff, Comparative Pathology of Inflammation, 1893. 

89 



90 INFECTIVE INFLAMMATIONS. 

Leaving open the question, whether true inflammation can occur 
in the absence of bacteria, it is certain that a vast majority of inflam- 
mations are due to or are characterized by the development of patho- 
genic organisms at some point — the area of infection. That is, when 
pathogenic bacteria gain entrance to the body and find a suitable soil, 
they undergo multiplication, they cause degeneration in the tissues ; 
inflammation with death of more or less tissue, and, after a period, re- 
generative changes occur. During the period of their growth sub- 
stances are formed which, being taken into the circulation, act as poi- 
sons (see Fever, Septicaemia, and Pyaemia). For example, in typhoid 
fever a specific bacillus gaining access to the glands of Peyer's patches, 
under favorable conditions multiplies and causes degeneration, inflam- 
mation, and cellular necrosis of the part, forming ulcerous patches. 
During the period of multiplication toxic substances are formed which, 
Avhen absorbed and carried by the circulatory fluids throughout the 
body, cause the train of symptoms peculiar to typhoid fever. The na- 
ture of the local changes induced and the general symptoms accompany- 
ing infection depend upon the nature of the infecting organism. The 
effects of pathogenic organisms as a class are, however, those above 
noted : local tissue-degeneration, inflammation, cellular necrosis, with 
symptoms of general poisoning ; at a later period regenerative changes 
occur which heal the injured part. This naturally divides the study of 
infection into two heads : first, local effects ; secondly, general symptoms. 

Suppuration. 

By far the most common and universal causes of infective inflam- 
mations are the pyogenic cocci (p. 45), organisms which, gaining access 
to the interior of the body, cause the formation of pus. According to 
their mode of grouping, these cocci are divided into two classes : first, 
the staphylococci ; secondly, the streptococci. The staphylococci are 
subdivided according to the color of their colonies in a culture-medium : 
the staphylococci producing orange-colored colonies are called staphylo- 
cocci pyogenes aureus ; those forming whitish colonies, the staphylococci 
pyogenes albus ; those causing lemon-colored growths, the staphylococci 
pyogenes citreus ; those giving green colonies, the staphylococci pyo- 
genes viriclis. The staphylococcus pyogenes aureus appears to be every- 
where. 

Bacteria may gain entrance to the body through wounds of the skin 
or of mucous membranes, or through any break or abrasion of these 
surfaces. They enter nearly every wound made, unless special precau- 
tions are taken to exclude them ; they are inhaled, and may be taken 
into the body from the respiratory tract ; they may be taken up from 
the alimentary tract. 



PLATE II. 




Abscess in Kidney of Rabbit after Intravenous Injection into an 
Ear-vein of Culture of Pyogenic Cocci. Dense mass of cocci 
surrounded by area of coagulation necrosis due to their toxic 
activity. Outside this a zone of phagocytes. 



SUPPURATION. 91 

It is of extreme importance to remember that a condition of perfect 
health in cells, tissues, and the body, is a safeguard against the attacks 
of any organisms which may gain entrance to the body ; and, vice versa, 
a susceptibility to their action is produced in the body, in its tissues, or 
in its cells, by a condition of debility of a part. This is notably true 
of hyperemia ; a part which is suffering from the degree of irritation 
which causes hypersemic debility, will fall a ready victim to the action 
of organisms which would probably not affect it in a condition of health. 
To take a simple example : the mouth of a sebaceous gland of the skin 
becoming occluded, there is no escape for the secretion, which accumu- 
lates and changes in character ; owing to the mechanical irritation of 
accumulated products, secretion is at first increased, until the acini 
and duct of the gland become much dilated ; the part becomes like a 
foreign body, is a source of irritation and active hyperemia results. Due 
to this cause, and, no doubt, to fermentative changes which occur in the 
accumulated secretion, a condition of lessened resistance is produced. 
The ever-present staphylococcus pyogenes aureus gains access to the 
gland, multiples, and causes the changes characteristic of an infective 
inflammation. The phenomena of inflammation occur — heat, redness, 
pain, and swelling ; there is a diapedesis of white blood-corpuscles 
with a fibrinous effusion, which in the presence of injured leucocytes 
coagulates. In the struggle between the invading bacteria and the 
leucocytes myriads of the latter have succumbed — have died ; the 
organisms secreting or excreting a substance capable of changing the 
(coagulated) albuminous effusion into liquid peptone, there results a 
fluid holding in suspension the leucocytes which have died, and the 
detritus of the tissue destroyed in the struggle ; the tissue-destruction 
proceeds in all directions, advancing most readily in the lines of 
least resistance, until the accumulated fluid, with the cells and detritus, 
are discharged. Occurring in a very small area, the process describes 
the origin, course, and termination of a pimple ; if a larger territory 
is involved, a boil ; in both cases the condition is one of abscess. The 
fluid discharged from the abscess is called pus. It consists of in- 
flammatory effusion, now fluid, having been transformed into pep- 
tone, the dead leucocytes, dead bacteria, and the remnants of broken- 
down tissue. This is the essential process of suppuration in any part : the 
entrance of pyogenic organisms into the tissues, the exciting of inflam- 
mation at some point of lessened resistance — a locus minoris resistentice, 
the death of tissues and leucocytes, the peptonizing of inflammatory 
effusions and breaking down of dead tissue, and the escape of the fluid 
thus constituted (Plate II.). 

It does not always happen that the pus finds escape, either naturally 
or through surgical aid ; the patient may die before this occurs (see 



92 INFECTIVE INFLAMMATIONS. 

Septicaemia), or the tissues beyond the seat of pus-formation, those in 
which the irritation does not exceed constructive hyperemia, mav form 
a boundary-wall which the organisms fail to break down and thus die — 
starved out ; the abscess-contents undergo changes, a cheesv or, in some 
cases, a calcareous mass marking the site (see Degenerations). 

While the staphylococci cause, as a rule, the circumscribed destruc- 
tion of tissue described, the streptococci, as, for example, the strepto- 
coccus of erysipelas, tend to multiply laterally, following the tortuosites 
of the connective tissue of the skin. They give rise to a progressivelv 
spreading violent inflammation, but do not cause a marked peptonizing 
of effusions and dead tissue — L e., but little pus is formed. 

Cause. — The cause of suppuration is the development in tissues of 
pyogenic organisms. 

Symptoms. — The symptoms of suppuration are both general and 
local. The local symptoms are, first, those of inflammation. At the 
height of the inflammation the apex of the swelling, hitherto of 
marked firmness, gives a feeling of lessened resistance, and later 
acquires a boggy softness. If the swelling be of marked size, dis- 
tinct fluctuation may be felt, showing the presence of fluid ; the apex 
of the swelling bursts, giving vent to the abscess-contents, when the 
inflammatory symptoms rapidly subside, the tissues lose their hardness, 
and usually regenerative changes occur, causing the obliteration of the 
abscess-cavity and tract ; or it may be that pus-formation continues after 
the subsidence of the inflammatory symptoms. The area of tissue-loss 
is called the abscess-cavity ; the pathway leading from the cavity to the 
point of discharge is called the fistula. 

General Symptoms. — The general symptoms of suppuration are 
caused by the absorption of the products of bacterial growth. These 
symptoms, if the suppuration be extensive, may be ushered in with a 
chill ; there may be fever as high as 104° F., a full, bounding pulse, 
and all the accompaniments of fever. In some cases of delayed evac- 
uation of the abscess there may be evidence of profound poisoning. 

Prognosis. — As a rule, abscesses tend to spontaneous recovery after 
evacuation, and in case a persistent discharge remains it is to be sus- 
pected that some portions of dead tissue have not been discharged, and 
that in minute crypts or crevices bacteria still develop. The occurrence 
of rigors (chills) and high fever is a danger-signal. A fluttering, weak 
pulse and clammy extremities following upon the primary fever are evil 
omens. 

Treatment. — When it is considered that the disease symptoms and 
dangers attendant upon the process of suppuration are due, in the first 
place, to the pyogenic organisms, and that the presence of pus and dead 
tissue is a source of debility and a detriment to the process of regenera- 



ULCERATION. 93 

tion, it is at once clear that the therapeutic indication is to rid the body 
of all of these substances ; that is, the evacuation of the pus is always 
the measure to be adopted. 

As soon as it is determined that pus is present in any accessible 
situation whatever, it should be given vent. If it be an abscess point- 
ing, as in a boil or over the root of a tooth, a sharp-curved bistoury 
should be passed through the top of the swelling and by a drawing 
motion a linear cut made, giving free exit to the pus. Even though 
the pus be not nearing a natural vent, if it is enclosed in the cancellated 
tissue of bone (osteomyelitis), or, as in alveolo-dental abscess, confined 
under the maxillary periosteum (see chapter on Alveolar Abscess), or be 
under the periosteum of the finger or elsewhere, an opening should be 
freely made into the infected area. As a rule, healing is spontaneous 
after the opening of an abscess, the discharge lessening gradually, and 
the cavity and exit being filled with granulation-tissue. In case the 
abscess-walls contain crypts in which bacteria may multiply, it may be 
necessary to use antiseptic washes to reach and destroy them. Hydro- 
gen dioxicl, in a 15 volume or 3 per cent, aqueous solution, is used to 
syringe out the cavity. Should the opening of the cavity be large, and 
there be danger of reinfection, it is advisable to pack the cavity with 
gauze impregnated with iodoform or aristol, or with the more recent 
iodin preparation, nosophen. Any dead tissue in the abscess must be 
mechanically removed, as regeneration will be delayed or prevented so 
long as the necrosed parts are suffered to remain. 

ULCERATION. 

The development of the pyogenic organisms upon a free surface 
causes tissue-degeneration and death, as described under abscess ; in fact, 
an abscess is a confined ulcer. 

Numerous forms of pathogenic organisms are capable of causing 
tissue-degeneration and death of a mucous or skin surface. If infection 
takes place through a hair-follicle, or if organisms develop upon an 
abrasion, or in the epithelium, in conditions of general or local debility, 
the epithelium is destroyed over an area, and in the subepithelial tis- 
sues the organisms multiply and cause tissue-loss. If the organisms be 
pyogenic — and ulcerous surfaces are usually infected by these bodies — 
pus is formed. Under some conditions, as in debilitated and neglected 
children, the ulcerous process may spread rapidly, as of the cheek in 
cancrum oris ; or when specific bacilli, which excite much sAvelling and 
quick death of the tissues of the cheek proliferate, causing the condition 
called noma. 

Treatment. — The general treatment of ulcers is to destroy the 
infecting organisms by antiseptic washes, such as a 1 : 2000 solution of 



94 INFECTIVE INFLAMMATIONS. 

mercuric chloric! in hydrogen dioxid, and subsequently washing the sur- 
face of the ulcer with some powerful antiseptic which destroys the 
superficial tissues and the bacteria in them ; for example, concentrated 
carbolic acid. The exposed surface is next covered with an antiseptic 
powder— iodoform, aristol, or nosophen (see section on Pharmacology) — 
and then the surface is to be protected from the access of organisms 
until the regenerative process has healed the breach. It is to be 
remembered, in this connection, that the reproduction of epithelium is 
from the epithelial boundary of the ulcer, for epithelium cannot develop 
from any but epithelial tissue. 

OSTEOMYELITIS. 

There is one kind of suppuration of more than ordinary interest 
to the dental practitioner, as beyond doubt many cases of maxillary 
abscess should be classed under this head — osteomyelitis, an inflamma- 
tion of the bone-marrow. 

Causes. — In conditions of debility pyogenic organisms, notably the 
staphylococci, and occasionally streptococci or pneumococci, or the bacil- 
lus tuberculosis, and in special cases the typhoid bacillus, 1 gain access 
to the cancellated tissue of bone ; they cause a thrombosis of the ves- 
sels about the area of infection, the bone-cells die, and suppuration 
ensues. 

Pathology and Morbid Anatomy. — In consequence of the growth 
of the organisms the adjoining vessels become thrombosed, the cells of 
the bone die — undergo coagulation-necrosis, 2 and the tissues are rapidly 
broken down into pus. The process spreads until the bone is perforated 
and the pus finds exit beneath the periosteum, which it separates from 
the bone unless the exit be immediate, and necrosis of that portion of 
the cortical bone results. If the process approach the nutrient artery 
of the bone, thrombosis of that vessel occurs ; and if it be a trunk of 
large size and of very limited anastomoses, as in the inferior dental 
artery, necrosis of the bone results. The case is one of abscess in 
peculiar anatomical situation, where the ordinary phenomena of inflam- 
mation can not be manifested. 

Symptoms. — The general symptoms of this condition are those of 
septic infection, combined with local evidences of marked disorder. 
There is debility with sharp hut ill-located pain, which may be followed 
by a chill, high fever, and a local inflammatory reaction of much 
severity ; the fever assumes the adynamic type. The pain becomes 
localized in the affected bone, and the duration of the symptoms will 
depend primarily upon the time required for the escape of pus, natu- 
rally or through surgical aid. When the superficial layers of a bone 

1 Park's Surgery, vol. i. 2 Ibid. 



FEVER. 95 

are affected or the infection is subperiosteal, it constitutes the condition 
known as acute infectious periostitis. 

Treatment. — The essential principle of treatment in all cases as 
soon as recognized is to gain access to the infected parts by incis- 
ing and drilling instruments, drain the cavity, remove dead tissue, 
and sterilize the cavity. 

Fever. 

The term fever is applied to a condition the most prominent feature 
of which is an elevation of the bodily temperature above the normal, 
37° C. To constitute a fever this rise in temperature must continue for 
some length of time. 

Causes. — Fevers are commonly caused by the presence in the circu- 
latory fluids of substances which act as poisons upon probably the nerve- 
centres controlling heat-production. As a rule, the offending substance 
is a poison generated in the body through the action of micro-organisms. 
The character and type of the fever are determined by the nature of the 
offending substances — i. e., the variety of infection. 

Classes. — Fevers are divided into periodic or continued, according 
as to whether there is a periodical fall of temperature and a subsequent 
rise, or whether the fever continues practically unabated from the begin- 
ning to the termination of a disease. Fevers are classed in severity 
according to the maximum temperature and again according to their 
duration. A temperature of 100.5° to 101.3° F. is called slightly febrile ; 
101.3° to 103° F., moderate fever ; 103°-105° F., marked fever. A tem- 
perature above 106° is termed hyperpyrexia. 

Symptoms. — The most characteristic symptom of fever is the eleva- 
tion of temperature ; accompanying this there is an increased frequency 
of the pulse. In acute inflammatory diseases the pulse is full and bound- 
ing, the eyes injected, the bowels constipated, and the urine scanty, con- 
taining an excess of urea. On standing, the urine throws down a brick- 
dust deposit (urates). In fevers of a lower type, or in many fevers 
which began as described, the high, bounding pulse is succeeded by a 
soft, quick pulse and evidences of great debility. In fevers in which 
the temperature runs high there is commonly evidence of intoxication, 
more or less delirium, and reflex muscular action. With a persistent 
temperature and a pulse becoming softer and more frequent, there is 
increasing debility. 

Pathology and Morbid Anatomy. — In all cases of continued high 
temperature the fat of the body rapidly disappears and granular degen- 
eration occurs in the muscles and viscera of the body. If the fever be 
long continued and of an adynamic type, this degeneration may become 
marked. Its occurrence in the muscles of the heart is common and is 



96 INFECTIVE INFLAMMATIONS. 

an element of danger. There are an increase in the amount of carbon 
dioxid formed and exhaled from the body, and an increased amount of 
oxygen inhaled. This, with the increase of urea, the product of the 
oxidation of nitrogenous tissues (muscles, glands, etc.), indicates that 
the oxidation of the tissues is largely increased; hence the elevation 
of temperature. As repair does not equal waste in fevers, the nutri- 
tive processes being profoundly disturbed, the essential elements of the 
tissues suffer from the increased oxidation and undergo degenerative 
changes. 

Prognosis. — The higher the temperature and the longer it continues 
the greater drain there is upon the vital forces. As a rule, a temperature 
of 106° F. persisting more than twenty- four hours presages death. If 
the vital forces flag and the heart-action becomes weakened, and if 
there be evidence of profound intoxication, such as twitching of tendons, 
low, muttering delirium, and a clammy surface, the outlook is bad. 
Favorable signs are falling temperature, a clear eye, tongue losing its 
coating, free action of the bowels, free perspiration, free action of the 
kidneys, and a good vascular tension. 

Treatment. — In the light of present knowledge, efforts should 
first be made to discover the nature of the cause of the fever and 
to remove it, if possible. If not, attention should be directed to main- 
taining the vital forces until the body rids itself of the offending causes. 
As many fevers are self-limited in course and duration, this latter treat- 
ment becomes an important consideration. Temperature should be kept 
within safe limits by the administration of antipyretics, when the con- 
dition of the heart will permit their being used, and also by cool spong- 
ing or cool baths. The action of the heart should be sustained by 
the administration of concentrated nutriment, and by stimulants when 
necessary. The bowels must be kept open. 

In any form of fever there is no therapeutic measure comparable 
with removal of the cause, provided this be discoverable, identified, and 

removable. 

Septicemia. 

Septicaemia is a condition in which septic matter is present in the cir- 
culating fluids of the body, and causes manifestations of widespread 
disorder. 

" The essence of septicaemia is a poisoning of the organism by toxins, 
toxalbumins, ferments, and other products of bacterial decomposition — 
i. e., it is septic intoxication." ] 

Varieties. — Conditions of septicaemia may be classified, according to 
the severity of the symptoms, as mild septic intoxication, septic poison- 
ing, and pyaemia. The nature and severity of the intoxication depend 

1 Ziegler, General Pathology, 1895. 



SEPTICEMIA. 97 

upon the nature of the poison — i. e., the variety of infecting organisms. 
The effects range from a slight increase of bodily temperature to a pro- 
found disturbance of the vital functions which ushers in death. They 
vary again from a transient intoxication to prolonged and constantly 
increasing evidences of poisoning. 

Causes. — Many of the cases described under the head of fevers 
might be fitly included under the head of septic intoxication — in- 
deed, fever is one of the prominent evidences of septic intoxication and 
their causes are similar. The causes of septic intoxication are the ab- 
sorption from one or more foci of bacterial development of toxic sub- 
stances which have been generated as the result of the vital processes 
of the organisms. Pathogenic organisms, in addition to local tissue- 
degenerations caused by their local action, induce these general symp- 
toms of disorder by the character of the substances produced by them. 
Bacteria may gain entrance to the body at some point, as at a wound, be 
taken up from some portion of the alimentary tract or from the lungs, 
and while causing but comparatively slight local evidences of disease at 
the point of entry, may develop in other portions of the body and gene- 
rate toxic substances in such situations. Miller 1 has recorded several 
forms of bacteria found in the human mouth which bring about pro- 
nounced septic poisoning when injected into the bodies of animals. 

Symptoms. — The symptoms, both general and local, of septic 
infection, as stated, depend upon the character of the poison in 
the circulation — i. e., by the variety of organism infecting. This 
may belong to any of the classes of bacteria capable of developing in 
any part of the body. It is only necessary that it be some form capable 
of transforming nitrogenous substances into simpler bases, which, if 
they gain entrance to the circulation from the tissues, alimentary canal, 
or respiratory tract, cause manifestations of the action of specific poisons. 
This is best illustrated by an examination of the products formed by the 
progressive decomposition of albumin. It is first peptonized, and, as 
pointed out by Brunton, 2 peptones directly injected into the blood cause 
poisoning. The substances formed in wounds, even those which go on 
to quick recovery, frequently cause an elevation of temperature when 
absorbed. The formation of compound ammonias (ptoma'ins) is a suc- 
ceeding stage of decomposition, in which such substances as sepsin, 
neuridin, tetanin, and ethyldiamin are formed, which are all active 
poisons. Next, simpler substances are formed, leucin and ty rosin, with 
the methyl-amins, and afterward such aromatic products as indol, the 
cresols, etc. Many of these substances may cause evidences of poi- 
soning. Some of them are formed in the alimentary canal, some 
in the tissues, and if they are absorbed and not promptly eliminated, 

1 Dental Cosmos, Sept., Oct., and Nov., 1891. 2 Croonian Lectures, 1888. 

7 



98 INFECTIVE INFLAMMATIONS. 

cause toxic symptoms. Pathogenic bacteria, such as the typhoid bacil- 
lus, the bacillus of tetanus, the bacillus of diphtheria, and others, cause 
the formation of albuminous bodies, allied to ptomams, much more pois- 
onous than the latter ; these substances have been called toxins or tox- 
albumins (Brieger). 

The general symptoms of septicaemia may be described as, first, affec- 
tion of the nearest lymphatic glands, in which the organisms become 
lodged. Infective inflammation occurs ; there is more or less fever, the 
height and character of which vary with the specific organism. In the 
more pronounced cases chills occur. There occur diarrhoea, and, as 
a rule, evidences of profound debility ; the heart-action and the pulse 
become rapid and weak, a clammy skin is noted, and disorder of the 
central nervous system is present. If the infection occur from a wound 
or an evident focus of inflammation, the wound-discharges become put- 
rid — i. e., show evidences of progressive decomposition. 

Treatment.— -The first consideration in treatment is the removal of 
the cause if possible, and the disinfection of the local disease-focus. 
Failing in this, or coincidently with it, the principle of therapeutics is 
to sustain the vitality of the patient until the eliminative functions of 
the body have disposed of the poisonous substances and their genera- 
tors (the micro-organisms). The general nutrition is to be supported 
by concentrated nutriments, beef peptonoids, protonuclein, sterilized 
milk, etc. The flagging heart-action is to be supported by stimulants — 
alcohol and strychnia. Brandy or whiskey is administered until the 
heart's action is found to grow more steady and vigorous. The intes- 
tinal tract is to be kept clear, and intestinal antiseptics administered — 
salol, naphthalin, and /9-naphthol. The temperature is kept within 
bounds by large doses of quinine and cool sponging. The mouth is to 
be freely sprayed with strong antiseptics : hydrogen dioxid, listerine, 
formalin (1 per cent.). 

Pyjemia. 

The word pyaemia (Greek puon, pus, and hcema, blood) does not 
imply the presence of pus in the blood, as might be inferred, but is used 
to designate a condition in which there is widespread pus-formation in 
areas of the body, each suppurating focus being at some point of the 
circulatory system. Toxic substances are formed at such foci, and com- 
plicate a general septicaemia ; the condition has been called septico- 
pyaemia. 1 

Causes. — Pyogenic organisms, exercising their specific action upon 
the walls of bloodvessels, cause inflammation of the walls and coag- 
ulation of the contained blood, which coagulum becomes infected by the 

1 Ziegrler. 



PYEMIA. 99 

organisms. Portions of the coagnlum become detached and are carried 
along the bloodvessels, setting up suppurative processes wherever the 
fragment happens to find lodgement. They are carried via veins to the 
lungs, and, stopping there, suppuration ensues ; carried into the pul- 
monary veins, they reach the heart, where they may excite inflamma- 
tion ; carried into the arteries, each point of arrest becomes a centre of 
suppuration. These organisms may find their way into the circulation 
in the manner described from any area of suppuration in the body in 
which veins may be engaged. 

Symptoms. — The symptoms of pyaemia are, in general, those of 
septicaemia, but, as a rule, their appearance is more delayed from the 
date of the reception of an injury or the outbreak of the primary sup- 
puration. The onset of pyaemia is usually by a chill or a succession of 
chills. Each fresh area of pus-formation is believed to be announced by 
a chill and a rise of temperature. The temperature is subject to remis- 
sions, and sudden variations in its height are noted. The general symp- 
toms are those of an adynamic fever. Local symptoms appear accord- 
ing to the point of lodgement of septic emboli. Pus-centres may be 
found in the lungs, and cause symptoms of dyspnoea ; collections fre- 
quently occur in joints, causing loss of mobility ; the swellings being 
apparent, eruptions appear on the skin ; typhoid symptoms become 
more pronounced, and an increasing debility ushers in a usually fatal 
ending. 

Treatment. — The treatment of pyaemia should be preventative. 
The carrying out of rigid antiseptic precautions has much lessened 
the frequency of pyaemia. If areas of infection are removable, they 
are removed no matter what extent of operation may be necessary. 
The general treatment is the same as in septicaemia, with much less 
hope of recovery. 

A consideration of the infective surgical processes in connection 
with dental and oral diseases is of the utmost moment to the practi- 
tioner of dentistry. Nearly all of the diseases which the dentist is 
called upon to treat are infective from their inception. Moreover, the 
saliva, holding in suspension numerous forms of bacteria, both sapro- 
phytic and parasitic, and their waste, is a highly infective fluid. 

It has been clearly demonstrated by the researches of Miller l that 
many forms of bacteria found in specific diseases, and found inhabiting 
the intestinal tract, are more or less constantly present in the human 
mouth, and that the pathway in many general infections is no doubt via 
the oral cavity. A wound made in the human mouth is necessarily an 
infected wound. In the vast majority of cases the body exercises its 
protective function in a phagocytosis, 2 which disposes of invading bac- 
1 Micro-organisms of the Human Mouth. 2 Hugenschmidt, Dental Cosmos, 1896. 



100 INFECTIVE INFLAMMATIONS. 

teria. In other cases it is beyond question that this protective provision 
fails and infection occurs. 

The principles, both pathological and therapeutic, which have been 
thus far expounded are the general principles upon which medical and 
surgical practice rests. They are in large part applicable to a proper 
and intelligent practice of dentistry. Dental practice is daily becom- 
ing more and more recognized as a special branch of surgery, the path- 
ology, morbid anatomy, and therapeutics of which are modified by 
peculiarities of structure and position as in any other specialty. The 
origin, structure, and function of dental parts being special and distinc- 
tive, their diseases and the treatment of their diseases are also necessarily 
specialized. Restating that in order to comprehend the nature of 
morbid processes in a part it is necessary to have a comprehension 
of the embryology, histology, physiology, anatomy, and physiological 
chemistry of the part, the transition is now naturally to a discussion 
of these factors in so far as their connection with disease-processes may 
be clear. 






SECTION II. 

ANATOMY AND DEVELOPMENT. 



CHAPTER VII. 



THE DEVELOPMENT AND STRUCTURE OF THE JAWS AND 

TEETH. 

Aberrations of Development. 
For a proper comprehension of many of the abnormal conditions 
found associated with the jaws and teeth some familiarity with the 
embryology and an intimate knowledge of the histology of the parts 

are necessary preliminaries. The jaws and 
teeth, or the modification of such structures, 
play an important part in the economy of 
nearly every class of animals. The jaws, de- 
signed for the seizing of prey, represent the 
first structures concerned in the process of 
nutrition. Specialized structures with which 
the jaws are armed, teeth or their modifica- 
tions, add to this primary armament and 

Fig. 44. 



ext: 



EXT. 




F.F. 



Diagram showing relations of 
epi- and hypoblast : H.F., 
head -fold; F.F., tail -fold; 
INT., hypoblastic layer of em- 
bryo; EXT., epiblastic layer ; 
PH.M., pharyngeal mem- 
brane. (Hertwig.) 




Diagrammatic outline of a human embryo of about seven 
weeks, showing the relations of the mandibular, mb, 
with the maxillary, MX, and olfactory processes, olf. The 
maxillary process is seen as an outgrowth from the 
base of the mandibular process. (Allen Thomson.) 



increase its usefulness. The teeth and jaws are so intimately associated 
that their embryology must be studied together. 

The embryology of the parts concerned with stomatology begins at 

101 



102 DEVELOPMENT OF THE JAWS AND TEETH. 

a very early period — before the twelfth day the future mouth may be 
located (His). The embryo, covered externally by an epiblastic layer, is 
traversed from near the tail-fold to near the head-fold by a tube lined 
with the hypoblast. At the tail- and head-ends of this tube the epiblast 
and hypoblast are fused together, forming septa ; the upper septum 
separates the future mouth from the future pharynx (PH.M., Fig. 43). 
The face and jaws are outgrowths and attachments to the primitive 
cranium, represented by the head-fold. Before the fourth week of 
gestation there appear beneath the head-fold four pairs of buds grow- 
ing toward the median line. From the uppermost of these growing 
processes (mb, Fig. 44) the lower jaw develops. From near the bases 
of these processes buds are given off, which grow obliquely forward and 
upward ; these processes are the embryonic upper jaw (mx, Fig. 44). 
At the same time a knob-like process grows downward from the end 
of the head-fold, and by the time the lower maxillary processes have 
united in the median line a cavern is formed between these several pro- 
cesses, which will form the future mouth and future nasal cavities. 
This corresponds with about the fourth week of gestation (Fig. 45). 
The globular processes growing downward form the intermaxillary 
processes from which the intermaxillary bones and the median portion 

Fig. 45. 



Sup. tubercle i|V J| .jfcjfc & . JUl 8u P- tl(berde 
Lateral tubercle TOiifflff fjjf WWe3 Lateral tubercle 




Head of an early human embryo, showing the disposition of the facial fissures and of the superior 

and lateral tubercles. (After His.) 

of the lip develop. The upper maxillary processes grow forward and 
inward, fusing later with the intermaxillary processes of each side (Fig. 
46, B). Each of these processes consists of a central mass of mesoblastic 
tissue — i. e., tissue out of which the several connective tissues of the jaw 
will develop bone, cartilage, muscle, and the ordinary connective tissues. 
As the superior maxillary processes grow forward to meet the de- 
scending intermaxillary processes, each sends inward a horizontal branch 
toward the median line, which progressively divides the large general 



ABERRATIONS OF DEVELOPMENT. 



103 



S.M.P; 



S.M.P. 



cavity into two compartments (N.C., nasal cavity, and O.C., oral cavity ; 
Fig. 46, A), and when these horizontal processes fuse in the median 
line with the descending maxillary 
(intermaxillary) processes the nasal 
and oral cavities are separated. 
These fusions occur about between 
the seventh and ninth weeks of 
gestation, the union at the forward 
end occurring first and progressing 
backward, the septum being com- 
pleted about the tenth or eleventh 
week. Malformations due to the 
non-union of the parts date, there- 
fore, from this period. Several 
types of deformity arise from the 
non-union or imperfect union of 
these parts. The horizontal or 
palatal processes may unite with 
one another and with the inter- 
maxillary processes, but their outer 
portions may fail to fuse upon one or both sides, constituting the 
condition known as harelip, shown in its extreme form in Fig. 47. 

Fig. 47. 




NAS. 




Complete bilateral fissures (coloboma) of face. (Guersant.) 

If the horizontal plates fail to unite with one another, an opening 
between the nasal and oral cavities remains, the condition being called 



104 



DEVELOPMENT OF THE JAWS AND TEETH. 



cleft palate. The intermaxillary processes may fail to unite upon, 
one or both sides with the superior maxillary processes proper, form- 
ing clefts which extend obliquely from the median line. As a rule, 
the outer or lip portions of these processes also fail to unite in this 
latter condition, so that oblique palatal clefts and harelip are commonly 
associated. If the right and left globular or intermaxillary processes 

Fig. 48. 




Median fissure of the lower lip and chin. (Marshall, after Wofler.) 

fail to unite with one another, a fissure will exist in the median line of 
the lip. It is rare that the right and left inferior maxillary processes 
fail to unite ; the condition is, however, occasionally seen (Fig. 48). 

Development op the Lower Jaw. 
The inferior maxillary processes have united in the median line 
beneath the partially developed buds of the superior and intermaxillary 
processes. The central portions of the mesoblastic tissue composing the 

bodies of these processes become transformed 
into two rods of cartilage, which act as sup- 
ports to the arch during the period in which 
the inferior maxillary bone is forming. The 
cartilages of the right and left sides do not 
fuse together at the future symphysis (Hert- 
wig) (Fig. 49). This cartilage is but a tem- 
porary structure ; it undergoes atrophy at 
about the sixth month of gestation, and at 
birth but few fragments are found near the symphysis. The end of the 



Fig. 49 




M.C 



Showing Meckel's cartilage (M C.) in 
longitudinal and transverse sec- 
tion. 



DEVELOPMENT OF THE TEETH. 



105 



cartilage in the base of the inferior maxillary process becomes the future 
malleus (one of the bones of the middle ear) (Fig. 50). The portion of 



Fig. 50. 




9 r f Isth gh 

Head and neck of a human embryo eighteen weeks old, with the visceral skeleton exposed. The 
lower jaw is somewhat depressed in order to show Meckel's cartilage, which extends to the 
malleus. The tympanic membrane is removed and the annulus tympanicus is visible, ha, 
malleus, which passes uninterruptedly into Meckel's cartilage, wk ; uk, bony lower jaw 
(dentale), with its condyloid process articulating with the temporal bone ; am, incus ; st, 
stapes ; pr, annulus tympanicus ; grf, processus styloideus ; Isth, ligamentum stylohyoideum ; 
kh, lesser cornu of the hyoid bone; gh, its greater cornu. Magnified. (After Kolliker.) 

the cartilage running from the malleus to the formed bony lower jaw 
becomes transformed into the internal lateral ligament of the inferior 
maxilla (Hertwig). 

Development of the Teeth. 
The first evidences of tooth-formation are seen at about the sixth 
week of gestation, at a period when the superior and inferior maxillary 
processes are but ill-defined masses of mesoblastic tissue surrounded on all 
sides by epiblastic tissue. Before the union of the processes which are to 
separate the nasal from the oral cavity and which form the future palate, 
is complete, the first evidences of tooth-formation may be observed. 
It is to be borne in mind that during the entire period of tooth-forma- 
tion other formative changes are in operation, out of which arise all of 
the parts associated with the teeth. A transverse section of the lower 
jaw at this period will exhibit an ellipsoidal surface in which there can 
be plainly seen a mass of indifferent mesoblastic tissue, surrounded by 
epiblastic tissue, except at the middle, where it is reflected over a pear- 
shaped structure — the future tongue (Fig. 51). Within the substance of 



106 



DEVELOPMENT OF THE JAWS AND TEETH. 



the mesoblastic tissue are seen two elliptical areas, the sections of Meckel's 
cartilage. If the sections are made near the median line, these oval 
areas will be close together ; if much farther back, they will be widely 
separated. On the upper surface of the jaw, upward and outward from 
Meckel's cartilage, the epithelium is seen to be much thicker at a point 
on each side than it is over other parts ; the free surface of the epithe- 
lium at this point rises above the general surface, and where the epithe- 
lium is in contact with the mesoblastic tissue it sinks below the general 



Fig. 51. 




A section through the developing jaws at about the seventh or eighth week : N. P., nasal 
process ; T., tongue ; M. C, Meckel's cartilage ; T. B., tooth-bands. 

surface (Fig. 51, T.B.). Sections made from before backward show that 
this dipping in and elevation of the epithelium extend along the arch of 
the jaw, so that if viewed from above it presents a horseshoe-shaped ridge 
occupying the summit of the embryonic jaw. The elevation is greatest 
in front, thinning gradually toward the heels of the horseshoe. This is 
the primary dental ridge. Older microscopists, notably Goodsir, obtained 
specimens from w T hich the epithelium had been removed, and hence the 
depression made by the base of the epithelial growth in the mesoblastic 
tissue gave the appearance of a groove, called by Goodsir the primitive 
dental groove. Sections made of older jaws exhibit the gradual evo- 
lution of the structures of the jaw. 



DEVELOPMENT OF THE TEETH. 



107 



The local overgrowth of epithelium proceeds until the ridge is well 

Fig. 52. 




Longitudinal transverse section of the inferior maxilla of a porcine embryo : b, band, solid at 
anterior portion, but divided posteriorly into band and lamina. (3 cm. X 40.) (Sudduth.) 

marked, and the lower epithelium — i. e., the germinal layer — is seen to 
sink deeper and deeper into the meso- -p t-o 

blastic tissue, forming a continuous 
horseshoe-shaped band of epithelium ; 
the epithelium in this condition is 
called a band (Fig. 52, 6). At a later 
stage the rounded base of the band 
becomes flattened; this base is then 
termed a lamina — the dental lamina. 
From the inner angle of this lamina 
ten buds are given off, each corre- 
sponding with a future deciduous 
tooth (Fig. 53, c). These ten buds, 
or, as they are called, dental cords, 
grow inward into the mesoblastic 
tissues, the anterior preceding in 
growth the posterior cords. Each 
developing cord appears soon to 
meet with an outlined resistance, corresponding roughly with the shapes 




Vertical section through band from jaw of 
porcine embryo : ep, epithelium ; b, band : 
c, cord ; d, connective tissue. (3£cm. X 60.) 
(Sudduth.) 



108 



DEVELOPMENT OF THE JAWS AND TEETH. 



of the several teeth. It might be said with perhaps equal propriety 
that the base of the cord assumes these shapes, as the origin of the 
assumption of the typical forms is unknown. The mesoblastic tissue 



Fic4. 54. 




Vertical section through band and cord of 3? cm. porcine embryo X 60: ep, epithelium with infant 
layer (il) ; 6, band ; c, pear-shaped cord ; dp, dental papilla ; ct, connective tissue. In this cut 
the walls of the cord are shown very plainly to be a continuation of the infant layer of the 
epithelium. (Sudduth.) 

is observed to be condensed, to be faintly differentiated, from the indif- 
ferent mesoblastic tissue ; this condensed area will ultimately form the 
dental pulp (Fig. 54). 

As the ingrowth of the epithelium proceeds, definite changes are seen 
to occur in the epithelial mass, which will later be described in detail. 
This epithelial mass is the structure through which the enamel of the 
teeth will be formed, and hence is called the enamel-organ. As it 
grows bodily inward, changes are observed in the tissues about it ; the 
indifferent mass of mesoblastic tissue, constantly increasing in size, is 
seen to undergo differentiations at isolated points ; bone-forming cells — 
osteoblasts — make their appearance and form bone without antecedent 
cartilage and without evidence of a periosteum ; this has been called 
interstitial bone-formation l (Fig. 55). Condensations of tissue occur 
about the outside of these several bone-islands, an embryo periosteum ; 
the development of the bony jaw is now in progress. It will be ob- 
served that Meckel's cartilage is not included in the area marked off as 
the bony jaw (Fig. 55). 

Outside the embryo periosteum evidences of the future muscles of 
the jaws appear. As the growth of the enamel-organ continues, and as 

1 Sudduth, in American System of Dentistry. 



DEVELOPMENT OF THE ENAMEL. 



109 



it assumes upon its inner surface the form of the future tooth, the con- 
nective tissue surrounding it acquires the character of a thick fibro- 
membrane, which later encloses the entire developing tooth-pulp and 
enamel-organ. These structures, out of which all of the dental tissues, 
with the exception of the nerves, will be evolved, are now collectively 
called the dental follicle. The growth of bone continues, so that the 




mc. e P- 

Vertical transverse section of jaw of porcine embryo, showing differentiation of periosteum : pp, 
periosteum of either jaw ; c.ct, follicular wall, appearing as a continuation of the periosteum ; b, 
band ; eo, enamel organs for premolars ; ep, epithelium ; db, developing bone ; mc, Meckel's 
cartilage. (5i cm. X 25.) (Sudduth.) 

ten follicles lie now in a gutter of bone, the developing maxilla. Before 
the enamel-organs assume their typical forms the cords from which each 
arose are each seen to give off a bud, which grows downward and inward ; 
as regards the first cords, they are cords out of which the enamel- 
organs of the permanent teeth will be developed. The cord of each 
temporary tooth gives off the cord of its permanent successor. Behind 
the cord for the second deciduous molars, and some writers have said 
directly from it, a cord arises for the first molar of the permanent den- 
ture ; this occurs before the sixteenth week. At about this period the 
epithelial bands connecting the enamel-organs with the surface epithe- 
lium of the mouth break up into whorls and connection between the 
developing teeth and mucous membrane is lost. 

Development of the Enamel. 

Each of the dental tissues is developed after a distinctive manner, 
and the process requires close observation with very high microscopic 
powers to make out all of the details. Although in point of time the 



110 



DEVELOPMENT OF THE JAWS AND TEETH. 



first layer of dentin is deposited before the first layer of enamel, the 
changes and evolutions which occur in the enamel-organ may be made 
out before the details of the structure of the dental pulp become appar- 
ent ; for this reason the development of enamel is first studied. 



Fig. 56. 




Vertical transverse section of jaw of porcine embryo, injected : ep, epithelium, with (it) infant 
layer : a, layer of ameloblasts ; o, layer of odontoblasts ; cp, cord for permanent tooth ; ot, outer 
tunic ; it, inner tunic ; sr, stellate reticulum ; wh. ep., whorls of epithelium formed from outer 
tunic and stellate reticulum ; d, dentin ; dp, dentinal pulp ; v, bloodvessels of pulp ; ct, con- 
nective tissue ; c. ct.. follicular wall ; p, periosteum ; sp, space. (10 cm. X 60.) (Sudduth.) 

It will be observed that the indipping of epithelium into the meso- 
blast is an indipping of the deepest or germinal layer of epithelial cells. 
It is noted at this period that while the epiblastic tissue is clearly 



DEVELOPMENT OF THE ENAMEL. 



Ill 



marked off from the mesoblastic, no such structure as a basement- 
membrane exists. As the dental cord increases in depth it increases 
in breadth, the germinal layers remaining distinct ; older cells make 
their appearance between the layers. Following the formation of 
the cords and their evolution into the enamel-organs, it is seen that 
the organ becomes first conical, the sides and base of the cone being 
formed of germinal epithelium ; a depression constantly increasing in 
depth forms in the base of the cone, until finally the enamel-organ is 
seen to consist of a double layer of germinal epithelium, the layers 
being separated by epithelial cells of an older type, which undergo 

Fig. 57. 




Section of a developing cuspid (human) at about the sixth month: A, ameloblasts; B, enamel; 
C, dentin ; D, odontoblasts ; E, stratum intermedium ; F, stellate reticulum ; Q, follicular wall. 

a remarkable increase in size. At this time, or a little later, blood- 
vessels make their appearance in the condensed mesoblastic tissues 
covered by the enamel-organ. Springing from the base of this con- 
densed mass, fibrous tissue makes its appearance, extending up and 
along the sides of the enamel-organ ; this is recognized as the wall of 
the dental follicle (Fig. 56, c.ct.). Between the fourth and sixth months 
of gestation the differentiation of the parts of the enamel-organ are evi- 
dent. The cells of the inner germinal layer of epithelium, that next to 
the mesoblastic tissue, are seen to assume a prismatic form, the change 
being most pronounced above the apex of the future pulp. The outer 



112 



DEVELOPMENT OF THE JAWS AND TEETH. 



epithelial layer for the present is of cuboidal cells ; between these two 
layers two types of epithelial cells are seen. The cells occupying the 
greater mass of the enamel -organ are greatly distended ; owing to the 
appearance of these cells when seen in section (Fig. 57, F) the structure 
has been called the stellate reticulum, or star-like network. It was at 
one time thought that the cells of this portion of the enamel-organ were 
devoid of cell-contents, the distention being caused by the accumulation 
of fluid between the cells. It has been lately shown l that the cells them- 
selves are enormously distended or enlarged (Figs. 57, 58). The layer 

Fig. 58. 




Section of developing tooth of an embryo calf: a. stellate reticulum of enamel-organ; b, stratum 
intermedium ; c, ameloblasts ; d, dentin ; e, odontoblasts ; /, bloodvessel— corpuscles in situ. 
X 275. (Williams.) 

of cells next to the pulp which have assumed the prismatic form are those 
through which enamel-building will be accomplished, hence they are 
called ameloblasts or enamel-builders. Between the ameloblasts and 
the stellate reticulum proper, the epithelial cells are of smaller size than 
those of the latter, are distinct, and are more firm. This layer is called, 

1 J. L. Williams, Dental Cosmos, 1896. 



DEVELOPMENT OF THE ENAMEL. 113 

from its position, the stratum intermedium. The fibrous tissue form- 
ing the follicular wall is observed in close relation with the outer epi- 
thelial layer of the enamel-organ. The structures necessary to the 
formation of enamel are now differentiated, but before this process can 
be comprehended a brief survey of the physiological chemistry of the 
operation is advisable. 

The enamel of the teeth, by present methods of chemical analysis, 
is found to be composed in large part of calcium salts, the phosphate 
and carbonate ; and yet in its structure and texture it in no way re- 
sembles the ordinary crystallized forms of these mineral salts, so that 
the formation of enamel is not merely the deposition and crystallization 
of calcium phosphate and carbonate. It is beyond question that enamel 
is a compound of organic origin, and the nature of its substance must 
be sought for among the organic compounds. 

The experiments of Harting, Rainey, and Ord, 1 have shown a 
reaction which no doubt has a direct bearing upon the formation of all 
calcified tissues. If to an albuminous solution a solution of a calcium 
salt be added, the calcium enters into chemical combination with the 
albumin, forming a substance indefinitely known as albuminate of cal- 
cium, and called by its discoverer calco-globulin. If calcium carbonate 
be formed in a solution of albumin, the above combination occurs, making 
definite structural forms, minute laminated spheres, which are called 
calco-spherites ; these spheres coalesce and form laminated masses — 
i. e., form in layers. When exposed to the action of dilute acids these 
spherites are more resistant than the crystallized salts ; moreover, after 
the action of the acid the form of the spherite remains. This chemical 
fact, the union of crystalloidal with colloidal substances, is, no doubt, 
of wide significance in general and special pathology, for it is extremely 
probable that the formation of all pathological concretions is an expres- 
sion of some such reaction. The evidence is strong that calcium albu- 
minate is the basis of all of the calcic tissues ; but precisely where 
its formation occurs in enamel-formation is unknown ; presumably, it 
occurs or is completed in the enamel-forming cells. 

Williams has shown, 2 by selective staining, that prior to and during 
enamel-formation the ameloblasts are separated from the developing 
enamel upon one side and from the stratum intermedium upon the 
other side by what appear to be membranes, so that any future genera- 
tion of enamel-cells, if such occur, must be from the ameloblasts them- 
selves. Moreover, the cells of the stratum intermedium are not of 
the germinal type. Andrews 3 calls attention to the fact that if a sec- 

1 R. R. Andrews, American Text-book of Operative Dentistry. 

2 Dental Cosmos, 1896, p. 107 et seq. 

3 American Text-book of Operative Dentistry, 1897. 



114 



DEVELOPMENT OF THE JAWS AND TEETH. 



tion of an enamel-organ at this period be placed under a cover-glass 
and a diluted mineral acid be permitted to run under the glass, bubbles 
of gas (carbon dioxid), are disengaged, showing the presence of calcium 
salts in the structures. The bubbles form in the stellate reticulum, 
in the ameloblasts, in the structure between the ameloblasts and the 
first-formed layer of dentin, and in the latter tissue. 

In the ameloblasts, having large, well-marked nuclei at their distal 




Section of developing tooth of an embryo calf: a, b, nuclei of reticulum of enamel-organ, showing 
spongiose character; c, outer ameloblastic membrane ; d, inner ameloblastic membrane ; e, /, 
enamel-globules faintly showing nuclear network, x 1000. (Williams.) 

portions two distinct cell-contents are seen : one, glistening droplets 
of various sizes, which coalesce, becoming larger as they approach the 
proximal end of the ameloblasts, out of which they are extruded against 
the forming dentin. In addition to these droplets the ameloblasts are 



DEVELOPMENT OF THE ENAMEL. 



115 



seen to contain one or more globular bodies, all of like size, lying 
between the nucleus and the proximal end of the cell. These globules 
are connected with one another by plasmic strings. Into the mass 
formed by the fusing together of the droplets first extruded from the 
ameloblasts, these uniform-sized globules are deposited. The first-named 
material, nominally calco-globulin, is a cement-substance which flows 
around and about the globules and their processes. The globules, from 
mutual pressure, assume naturally a prismatic form. The globular 
bodies are called by Williams enamel-globules. The small droplets 
out of which the cement-substance is formed are found also in the 
stratum intermedium ; differential staining demonstrates this. The 
enamel-globules stain differently, are of one size, and are only noted 
between the nucleus and the proximal end of the cell. Williams infers 
that they arise by a process of mitosis or cell-multiplication from the 
nucleus itself, a most rational conclusion. As soon as the first layers 
of enamel have formed . a notable change is seen to occur in the 
enamel-organ ; the stellate reticulum disappears over the forming 
enamel. The calcic material stored in its cells has been exhausted in 
forming the first layer of enamel ; the succeeding enamel has a different 



Fig. 60. 




Section of incisor of rat : a, capillary loops torn out of secreting papillae ; b, secretin.? papillae after 
removal of capillary loops ; c, ameloblasts ; d, enamel ; e, dentin. X SO. (Williams. | 

source of formative material. The stellate reticulum atrophies and the 
outer boundary wall of the enamel-organ comes in apposition with the 
stratum intermedium. Williams observed in the enamel-organs of rodents 
(Fig. 60) that the cells of the stratum intermedium become arranged 
over loops of vessels from the vascular coat, so that papillae are formed. 
He infers that a similar arrangement occurs in the enamel-organ of man ; 
and that the function of the papillary structure is the selection from the 
blood-plasma of material to be passed into the ameloblasts out of which 



116 



DEVELOPMENT OF THE JAWS AND TEETH. 



the enamel is formed. The deposition of cemen ting-substance and 
connected globules continues, and the enamel increases in thickness 
from the dentin outward (Fig. 61). The enamel over the tips of the 



Fig. 61. 




Mode of enamel-deposition: A, formed enamel; B, ameloblasts ; C, secreting papillae of stratum 
intermedium: D, bloodvessels in external fibrous coat and to secreting papillae- .E, enamel- 
globules with connecting plasmic strings ; F, nuclei of ameloblasts ; G, odontoblasts ; H, blood- 
supply to odontoblastic layer ; I, unformed dentin: J, formed dentin. Semi-diagrammatic. 
(After 'Williams.) 

teeth is first formed, and as this portion of enamel increases in thickness 
successive portions of the ameloblastic layer acquire formative function ; 
the covering stellate reticulum gradually disappears, until by the time 
the neck enamel begins to form no vestiges of the stellate reticulum 
remain. This deposition of substance continues until the crown of the 
tooth has its normal form, the ameloblasts appearing to undergo partial 
calcification themselves, resulting in the formation of a continuous sheet 
covering the enamel, and constituting, at least in part, Nasniyth's 
membrane. 

Formation of Dentin. 

Prior to the appearance of any calcic tissues in the teeth, it is noted 
that upon the periphery of the developing pulp, notably in the positions 
of the future cusps, a layer of cells becomes differentiated from the in- 



FORMATION OF CEMEXTUM AXD ROOTS OF TEETH. 



117 



different mesoblastic tissues of the pulp ; these cells assume an arrange- 
ment like that of cylindrical epithelium, but are not in lateral contact 
with one another. Beneath this layer of cells, called from their 
function the odontoblasts (pdous and blastos), a capillary network is 
formed, the capillaries extending by loops into the odontoblastic layer 
(Fig. 61). Before any deposition of enamel occurs it is seen that the 
odontoblasts exude and extrude from their distal ends masses of calco- 
spherites. As this deposition proceeds the odontoblasts recede, each 
cell leaving one or more branched processes in the dentin-deposit. 
The deposition continues, the dentinal pulp constantly decreasing in 
volume as the dentinal deposit increases in amount. "When it is 
remembered that the deposit of dentin begins before that of the enamel, 
it explains how the processes from the odontoblasts may be found in 
the enamel in exceptional cases ; the processes may grow outward be- 
tween the ameloblasts, and a deposit of enamel occur about them. This 
condition, normal in the teeth of some animals, is occasionally seen in 
the teeth of man. 1 



Formation of Oementum and Roots of Teeth. 

The deposition of cementum begins after the formation of enamel is 
practically complete. The formation of cementum is identical with the 

Fig. 62. 




A, developing bone ; B, tissue reflected from follicular wall and forming alveolar periosteum ; 
C, follicular wall ; D, vessels and nerves ; E, epithelium of gum. 

subperiosteal formation of bone. By the time that enamel-formation 
is complete, or nearly so, the greater bulk of the crown dentin has been 

1 Williams, Proc. Odontological Society of New York, 1896. 



118 DEVELOPMENT OF THE JAWS AND TEETH. 

formed and the dental pulp is contracted from above, less upon the 
sides, and is widely open beneath. The developing teeth at this stage 
rest in a gutter of bone, which at present makes up the greater bulk of 
the inferior maxilla. The bases of the teeth are not far removed from 
the canal containing the nutrient vessels and nerves ; the inferior dental 
canal — that is, the neck of the tooth — is in the position which will be 
occupied by the apex of the root after the tooth is fully formed." It is 
evident, therefore, that the growth of the root of the tooth must mean 
its extension upward, the only direction in which it is free to move, it 
being observed that the gutter of bone in which the teeth lie is not com- 
pletely closed above (Fig. 62). It is asserted by Hertwig 1 that the ex- 
tremity of the enamel-organ grows downward beyond the crown of the 
tooth, so that the following relationship is established : a layer of 
odontoblasts is found upon one side of this epithelial layer ; upon its 
other side the follicular wall comes in close apposition. The epithelial 
sheath atrophies, and is probably the source of the epithelial Avhorls 
found in the pericementum. The deposition of root -dentin begins 
before any cementum is formed, the first deposited portions of dentinal 
matter being frequently marked by faulty organization, forming the 
line of imperfect calcification known as the stratum granulosum. The 
fibrovascular covering of this portion of dentin becomes a modified peri- 
osteum ; a layer of osteogenetic cells appears upon the portion next to 
the dentin. These cells, from their function, are called cementoblasts ; 
they lie as flattened cells, between which large fibres from the fibro- 
vascular portions of this tissue pass. The fibrovascular osteogenetic 
tissue spreads over the developing bone about the forming tooth, and is 
thus both alveolar periosteum and pericementum. The croAvn of the 
tooth is thrust forward as the root develops, and no doubt the gradual 
growth of the bone about the teeth is also a factor in the movement of 
the tooth. The remainder of the process will be discussed under the 
head of dentition.. 

By the time the crowns of the teeth have made their appearance 
through the gum the root-formation is still incomplete. As the crown 
of the tooth advances the bone which overlays the crown undergoes 
sufficient absorption to permit the passage of the crown, the bone being 
at other parts separated from the tooth and its partially formed root by 
the thick layer of connective tissue, forming pericementum and alveolar 
periosteum. Deposition of dentin and cementum continues until the 
root-form is complete ; after eruption, bone-formation about the tooth 
reduces the thickness of the pericementum and sheaths the roots of the 
teeth in a bony covering. 

The development of the permanent teeth follows a similar course ; 

1 Rose, Dental Cosmo*. 1893. 




LATER DEVELOPMENT OF THE MAXILLM. 119 

beginning with the follicle of the first permanent molar, which is dif- 
ferentiated between the fourth and fifth months of gestation, situated 
behind the developing deciduous second molar. The f o 63 

enamel-organ of the second permanent molar arises from 
the cord of the first, between the seventh and eighth 
months of gestation ; the enamel-organ of the third perma- 
nent molar, arising in its turn from the cord of the 
second molar, does not appear until about the third year. 
The cords for the other permanent teeth — incisors, cus- 
pids, and bicuspids — appear as offshoots from the cords 
of the temporary teeth which they are to succeed, at 
from the fourth to the fifth month. At the time of 
birth the follicles of these teeth are complete, and calci- lation of per- 
fi cation begins shortly thereafter. The development of ^f, 116 , 111 too1 ; h " 

° J _ L follicle to the 

the temporary teeth is accomplished in a period averag- root of the tent- 
ing about three years ; that of the permanent teeth re- P° rar y t( 
quires for the first formed tooth about seven years, and for the last 
formed about fourteen years. 

The developing permanent teeth are situated behind and beneath the 
temporary teeth (Fig. 63), the development of bone about the follicles of 
the permanent teeth enclosing each of them in a distinct pocket of its own, 
a bony lamina existing between each follicle and the tooth-root adjacent. 
It is to be noted that the developing permanent teeth are separated 
from the inferior dental canal by a lamina of bone ; the canal, it will be 
seen, has in the child at birth but comparatively little thickness of 
covering-bone beneath it — i. e., the body of the bone is very slight. 

Later Development op the Maxilla. 

The maxilla? have developed during the period included in the 
foregoing description mainly as tooth-carriers and supports ; the 
maxilla? proper have not developed to a corresponding degree. The 
body and rami of the lower jaw represent only the lesser portion of the 
entire maxillae ; the body of the upper jaw is at all aspects but a 
diminutive of the mature jaw. 

At the time of birth Meckel's cartilage has disappeared, but a few 
fragments are left about the symphysis. The site of this anatomical 
scaffolding is represented by the mylohyoid groove, a groove beneath the 
inferior dental canal, which lodges the mylohyoid branch of the inferior 
maxillary nerve. As stated, the alveolar portion of the jaw forms its 
major and most prominent part. The body and rami of the bone are at 
a very immature stage. The body of the bone, that beneath the alveolar 
portion, is a comparatively small and thin shell of bone, something- 
more than sufficient to accommodate freely the inferior dental artery, 



120 



DEVELOPMENT OF THE JAWS AND TEETH. 



nerves, and veins which it encloses. The rami of the jaw are very 
short. The coronoid process arises to but a small height, and almost 

Fig. 64. 




Representing a jaw of a nine months' foetus, superimposed on an adult's jaw, to show in what 
directions increase has taken place. (Tomes.) 

immediately behind the covering of the second deciduous molar follicle ; 
the condyloid process is at about the same height, but little above the 

Fig. 65. 




Showing the relative sizes of jaws at the age of two years and in the adult. 

level of the gum-summit, there is not that sharp distinction between 
ramus and body seen at later stages. 



DEVELOPMENT OF THE UPPER JAW. 121 

If the inferior maxillae of an infant at the time of first dentition be 
compared with that of an adult, it will be seen that the radii of the dental 
arches in both jaws are nearly alike. The comparison may be more 
readily made if the two jaws be compared at the completion of the 
primary dentition (Figs. 64 and 65). It will be observed that the body 
of the mature jaw projects very much at the anterior and lateral aspects 
of the jaw, but the greatest amount of growth is backward and upward ; 
these are, therefore, the directions in which the greatest growth occurs. 
The coronoid process, which at two years is but little behind the second 
temporary molar, recedes, until at about the age of seventeen years the 
space between the ramus and the former position of the second deciduous 
molar is sufficient to accommodate the three largest teeth of the dental 
series. 

The depth of the jaw, the portion of the jaw lying beneath the men- 
tal foramen, is nearly acquired by the seventh year ; the height of the 
jaw (the portion above) is not acquired until some time after the full 
eruption of the permanent teeth. From the time of birth, the anterior 
portion of the body of the jaw — that in front of the mental foramen — 
develops, as shown in Fig. 64, by additions to its front wall. The not- 
able increase is backward and by an upward movement of the rami. 
The direction of the movement of the condyle during development is 
obliquely backward and upward. " The condyle occupies during devel- 
opment of the jaw, successively, every point of the internal oblique 
line." l 

" The course of the coronoid process is to be seen in the external ob- 
lique line." 2 The formation of the condyloid portion of the bone is 
largely cartilaginous, the formation of the other growing portions of 
the bone being almost entirely subperiosteal. There is a complex ac- 
companiment of resorption with deposition, in the formation of the rami 
of the lower jaw. The amount of bone deposited during the growth of 
the ramus of the jaw would represent a quadrangular block the thickness 
of the condyle, and extending backward from the posterior surface of 
the second bicuspid to the back edge of the jaw, and from the alveo- 
lar border to the height of the condyle at maturity ; but as the depo- 
sition of bone occurs backward and upward, the redundant deposit 
undergoes an absorption which carves the bone into its typical form. 

Development op the Upper Jaw. 

Observations as to the exact mode of development of the upper jaw 
are not so complete as those relating to the lower jaw. At the begin- 
ning of tooth-formation in the upper jaw the junctions between the 
right and left palatal processes, and of the intermaxillary processes 

1 C. Tomes. 2 Ibid. 



122 



DEVELOPMENT OF THE JAWS AND TEETH. 



with both, have not occurred. In the intermaxillary portions the fol- 
licles for the incisor teeth are formed. After the junction of the several 
processes the palatal curtain becomes differentiated into two parts : the 
anterior undergoes ossification ; the posterior remains as a movable cur- 
tain — the soft palate. There occurs an interstitial formation of bone 
outlining the dental portion of the superior maxillse, and soon a peri- 
osteum appears as in the lower jaw. 

At the time of birth the upper jaw is at a stage of immaturity 
corresponding with that of the lower jaw. The partially formed 
crowns of the temporary teeth, the incisors, farthest advanced in devel- 
opment, next the first molars, then the cuspids, and finally the second 
molars, are all enclosed in a hollow arch of bone, having transverse 
divisions between each tooth ; the spaces, or, as they are called by 
Tomes, loculi of the several teeth, are outlined in the degree of the tooth 
development (Fig. Q6). Behind the second molar is the developing 

Fig. 66. 




Jaws of a seven months' child. The incisors in both maxillae are being erupted by the absorption 
of the gum from their cutting edges and the elongation of the roots by calcification. (Tomes.) 

first molar of the permanent denture ; as in the lower jaw, the dental 
portion of the bone predominates. Taking the infra-orbital foramen as 
a fixed point of measurement, the top of the alveolar arch is but a 
short distance from the floor of the orbit, At the time of birth the 
roof of the mouth is but slightly arched from side to side. We may 
regard, as in the lower jaw, the main portion of the superior max- 
illae at this stage of development to be a dentale, an alveolar portion ; 
and that the body of the bone, as in the lower jaw, is in a foetal con- 
dition ; but when it is observed that the developing teeth are almost 



HISTOLOGY OF THE MATURE TEETH. 123 

on a level with the palatal processes, it is evident that these teeth are 
lodged in the maxillae proper, and that the course of development cre- 
ates the major portion of the alveolar bone subsequently. This is nota- 
bly true of the follicles of the permanent cuspids, which occupy a posi- 
tion high up and behind the roots of the temporary tooth. A pair of 
dividers having one point in the infraorbital foramen, and the other 
measuring from that point to, first, the symphysis edge, and next to the 
p6sterior alveolar edge will show, if applied to jaws of successive ages, 
a lengthening in both directions. The increase is most notably down- 
ward. The teeth shift their relations not only to their early environ- 
ment, about the level of the palatal vault, advancing toward the al- 
veolar border ; but, in addition, the developing alveolar process lengthens 
the distance from the alveolar border to the infra-orbital foramen, not 
alone the alveolar process as generally understood, but the alveolar seg- 
ment of bone itself increases in size, until the bone has the dimen- 
sions found in the adult. Measurements at this time show that the 
distance from the infra-orbital foramen to the alveolar border is greater 
than the depth of alveolar process developed. 

Histology of the Mature Teeth. 

It is only through a study of the embryology of the teeth that the 
histology of their tissues becomes clear, and following the course of their 
development fully explains the structure of enamel, dentin, and ce- 
m en turn. 

ENAMEL. 

Sections of enamel show the tissue to be apparently made up of 
hexagonal prisms, which until recently were believed to be homogeneous 
throughout their length. Upon the theory that enamel consisted of the 
calcified bodies of the ameloblasts, hexagonal prismatic epithelial cells, 
there could be no other deduction ; but the researches of Andrews, who 
demonstrated the interlacing basement-stroma of enamel, and the later 
work of Williams, which showed the duality of enamel-substance, ren- 
der untenable the theory of continuous, homogeneous prisms. The 
final blow at the direct calcification theory, it will be recalled, is that 
the axes of enamel-rods and' of the ameloblasts are at wide variance. 
An optical analysis of mature enamel in properly prepared specimens 
shows clearly the presence of two substances (Fig. 67). The clear 
spaces in the section are the cementing-substance binding together the 
calcified globules, shown dark in the section. It will be seen that these 
globules are superimposed upon one another in such a manner as to form 
rods marked by transverse lines. These rods were formerly called 
enamel-prisms. If a section be subjected to the action of a dilute min- 



124 



DEVELOPMENT OF THE JAWS AND TEETH. 



eral acid (HC1), the cement-substance between the rods and between the 
individual globules dissolves more rapidly than the substance of the 
globules, and there is produced the beaded appearance shown in A, 

Fig. 67. 




Section of enamel of human tooth. Photographed with Zeiss apochromatic lens and Powel and 
Leland apochromatic condenser. The optical parts accurately centred and the focus " critical." 
The enamel-rods are seen to be resolved into distinct sections (enamel-globules), the cement- 
substance often passing entirely between the sections. X 400. (Williams.) 

Fig. 68. Sections cut transversely to the long axis of the rods exhibit 
the appearance shown in B ? Fig. 68. The action of the dilute acid 

Fig. 68. 
A 





Enamel-prisms: A, fragments and single fibres of the enamel isolated by the action of hydro- 
chloric acid ; B, surface of a small fragment of enamel, showing the hexagonal ends of the 
fibres. X 350. 

upon such specimens causes enlargement of the spaces between the 
hexagons by dissolving the cementing — the interprismatic — substance. 



HISTOLOGY OF THE MATURE TEETH. 125 

The enamel of human teeth, and, indeed, that of animals, dif- 
fers in the relative amount of cementing-substance and the number 
of globules, and, again, in the regularity of the distribution of the two. 
In one specimen the globules may so predominate that the cementing- 
substance shows in sections as fine lines, in others the globules may be 
small, rounded, and surrounded by a relatively large volume of cement- 
ing-substance. Again, at different parts of the enamel-rods both ar- 
rangements as to relative amounts of the two substances may be seen. 
It is an apparently constant fact that the cementing-substance is more 
soluble in dilute acids than is the substance of the calcified globules. 

" When enamel deposition proceeds with the utmost regularity stria- 
tion of the rods is most evident and most regular — i. e., is best marked 
in perfect specimens of enamel, the striation representing the orderli- 
ness with which the layers of globules are deposited " (Williams). 

The enamel-rods are crossed at an angle by transverse brown bands, 
the striae of Retzius. These are, as compared with the size of globules, 
broad bands which exhibit parallelism with one another ; they are 
pigmentary deposits. The causes of their presence are not known, but 
it is probable, from existing evidence, that they represent periodical 
alterations in the process of enamel-development. They almost follow 
a series of lines which represent the outer boundary of the enamel -cap 
at different stages of development ; that is, they are most abundant in 
number in the thickest portions of enamel ; least so in the thinnest por- 
tions about the necks of the teeth. Noting the mode of formation 
of the rods, it is evident that they must have a radial direction from 
the dentin surface outward ; the rods are, however, not straight, but 
pursue an undulating course — i. <?., each rod is wavy. In the cusps of 
teeth, bicuspids and molars, the general direction of the rods is altered, 
so that they appear to interlace in sections. 

When the crowns of teeth have fully erupted, what remains of the 
enamel-organ is entirely cut off from its source of nutrition, and in 
all probability nutritive supply to this tissue ceases prior to the erup- 
tion ; it is evident, therefore, that any change which occurs in the 
enamel after the eruption is entirely apart from nutritive influence. The 
enamel contains at this time all of the materials entering into enamel- 
composition. It has been asserted in the past, and, indeed, is even 
believed at the present time, that the enamel undergoes changes of 
structure with age — grows harder. Cut off from its nutritive source, 
the only possible way in which change could occur would be in a molec- 
ular alteration of the substance of Avhich enamel is formed. Premis- 
ing that no change whatever occurs in enamel after the disappearance 
of the enamel-organ at the completion of amelification is an entirely 
warrantable position, and yet the possibility of such a molecular rear- 



126 



DEVELOPMENT OF THE JAWS AND TEETH. 



rangement as would alter both the physical and the chemical properties 
of enamel-substance must be conceded. Whether or not enamel does 
grow harder after its formation is undetermined. 



THE DENTIN. 

Sections of formed dentin show it to be made up of a calcified basis- 
substance penetrated throughout its thickness by tubules. The latter 
exist in such profusion as to occupy in some specimens nearly as much 
space in the section as is occupied by the basis-substance itself (Fig. 69). 
In other teeth, presumably those having a less percentage of organic 
matter, the basis-substance of the dentin predominates. The tubules 

Fig. 69. 




Longitudinal ground-section through the crown of a cuspid of a man set. 23. Wet ground-section 
stained by Golgi's method: J, interglobular space ; 8, enamel. X 250. (Rose.) 

pursue a continuous, wavy, radial course from the periphery of the pulp- 
chamber to the junction of enamel and dentin. Near their termination 
at the enamel the tubules divide and subdivide dichotomously. In 
sections prepared after the Weil method, which makes possible the 
preparation of laminae composed of hard and soft tissues and outlines 
both by means of differential staining, or, in this case, by the Golgi 
method, it is seen that these dichotomous branches take stain as do 
the contents of the tubules — i. e., they are the same substance. A 
transverse section through the dentin exhibits sections of the tubules 
(Fig. 70). In this specimen saturation of the dentin with Canada 
balsam preceded the staining, so that the tubules are filled with 
unstained balsam, showing white. Two distinct substances are seen : 



HISTOLOGY OF THE MATURE TEETH 



127 



immediately bounding each tubule is a thick layer of substance stained 
dark, and between these circular areas of staining are more faintly 
stained areas. If sections be subjected to the action of dilute acids, it 
is seen that the basis-substance of the dentin is dissolved much more 
rapidly than the surrounding walls of the dentinal tubuli — i. e., the 
walls of the dentinal tubuli diifer in composition from the basis-sub- 
stance of the dentin. These walls are called, from their discoverer, the 
sheaths of Neumann. " If dry and macerated specimens of dentin be 
subjected to the action of dilute acetic acid (Baume), the sheaths of 



Fig. 70. 




X.Sch 



Transverse ground-section through the dentinal tubules of the first molar of a child aet. 7: 
V. Koch's and Golgi's methods combined. X1200. (Rose.) 



Neumann around adjoining tubules are seen to be connected with one 
another by numerous transverse branches." ! Specimens stained after the 
Golgi method showed that these transverse connections take stain like the 
sheaths of Neumann, but that no evidence of the entrance of filaments 
of Tomes' fibres can be observed, Tomes' fibres being the organic 
central contents of the dentinal tubule (see later). These transverse 
branchings are most evident in the most recently formed dentin ; least 
evident in the oldest or peripheral dentin. This virtually marks off 
the recently formed dentin into defined areas of fully calcified basis- 
substance, each of which is surrounded by the substance of which 
Neumann's sheaths and its branches are composed. From its reaction 
to stains and its behavior toward acids this latter substance is re- 
garded as a transitional material between fully calcified dentin and 

1 Rose, Dental Cosmos, 1893. 



128 DEVELOPMENT OE THE JAWS AND TEETH. 

its organic basis, and a structure quite explicable through the embry- 
ology of dentin. 

Specimens of dentin subjected to the prolonged action of a 6 per cent, 
solution of acetic acid do not lose their form, but become pliable, the cal- 
cium salts having been removed from the organic matrix. Rose states 
that if a section of decalcified dentin be placed on a cover-glass and 
concentrated nitric acid applied, and the slide warmed, the substances 
between the sheaths of Neumann and their connecting branches melt 
away ; next the connecting branches disappear, and finally the sheaths 
themselves. In old specimens of dentin there is no evidence of the 
presence of transverse branches of Neumann's sheaths until sections 
are subjected to the action of dilute acids, when by the formation of 
bubbles of carbon dioxid their presence becomes evident. This point 
is of clinical significance, as it demonstrates that there are in the den- 
tin lines of less resistance to the action of acids. 

It has been shown by Hart 1 that the basis-substance of dentin is 

Fig. 71. 




Main mass of dentin of a temporary tooth, stained with chlorid of gold, decalcified with acetic 
acid: F,F, dentinal fibres, partly vacuoled ; B,B, basis-substance, traversed by a reticulum. 
X 1200. 

traversed by a fine network of fibres, a connective-tissue stroma in 
which the calcific process occurs (Fig. 71). Rose 2 regards these as 
the gelatin-yielding fibres of the dentin. 

In the border-ground between dentin and enamel and dentin and 

1 Dental Cosmos, 1891. 2 Dental Cosmos, 1893. 



HISTOLOGY OF THE MATURE TEETH. 



129 



cementum the dentin usually presents a different histological appearance 
from the general mass of the dentin. Instead of the orderly sub- 
division of the dentinal tubules, this portion of the dentin may be occu- 
pied by irregular spaces — interglobular spaces. This particular layer 
of tissue was named by its discoverer, Sir John Tomes, the granular 
layer (Fig. 72). As he pointed out, the layer is much more marked 

Fig. 72. 




Ground-section through the root of a human premolar : D, dentin ; K, cement-corpuscles ; 0, osteo- 
blasts ; Ep, remains of Hertwig's epithelial sheath ; J, interglobular spaces. X 200. (Rose.) 



beneath the cementum than beneath the dentin. (These spaces will 
be discussed in Chapter X.) It was first pointed out by the same 
observer that the organic processes contained in the tubules of the den- 
tin were direct prolongations from the peripheral cells of the dental 
pulp ; that they were processes of the dentin-forming cells — the odon- 
toblasts ; these processes are named, from their discoverer, Tomes' 
fibres. Investigations as to the nature of these fibres have thus far 
defined them as protoplasmic processes ; they are not connective- 
tissue fibres, and their identity with nerve-fibres is disproved, although 
their high degree of sensitivity favors such a conclusion. The general 
direction of the tubules is at the necks of the teeth and in their root- 
portions at right angles with the axis of the pulp-chamber ; in the 



130 



DEVELOPMENT OE THE JAWS AND TEETH. 




Margin of dental pulp: a, a, dentinal fibrils, pulled out of the dentin; b, b, membrana eboris or 
layer of odontoblasts ; c, c, transparent zone between the odontoblasts and the cells of the pulp 
proper: d, d, layer of cells closely packed together; e, e, bloodvessels; /,/, cells less closely 
placed toward the central portions of the pulp. (Wales' immersion, & in. objective.) (Black.) 



Fig. 74. 



S.D.- 



Od.- 



N.T.- 



B.V.~i 



!&**# 






.. . 





l-iV.F 



C.G 



Section of a tooth-pulp : B.V., main bloodvessels of pulp; C, origin of capillaries; N.T.. main 
nerve-trunk; N.F., subdivisions of nerve into fibrillse ; O.D., odontoblastic layer; S.D., sec- 
ondary dentin ; C.G., masses of calco-globulin. X 30. (After Rose and Gysi.) 



HISTOLOGY OF THE MATURE TEETH. 



131 



crown portion they proceed radially, the centre of the pulp-chamber 
being the centre of radiation. 



THE PULP. 



As foreshadowed in the embryonic tissue of the dentinal papilla, the 
dental pulp consists of a connective-tissue stroma, an interlacing vas- 
cular network, a layer of differentiated formative cells, and a neural 



Fig. 75. 



CD. 



L.F. 




Section of pulp, showing the relations of the odontoblasts to the dentin : Od., odontoblasts ; 
T.F., Tomes' fibres— odontoblastic processes; I.D., uncalcified dentin; CD., calcified dentin; 
P. C, pulp-cells. X 800. (Rose and Gysi.) 

system. Thus far, no evidences of a lymphatic system have been dis- 
covered (Fig. 73). 

The general disposition of the tissues of the pulp is as follows : a 
layer of columnar cells — the odontoblasts — covering its periphery and 
sending processes — Tomes' fibres — into and throughout the lengths of 
the dentinal tubule ; beneath this layer a closely interlacing plexus of 
non-medullated nerve-fibres and a capillary network. The middle por- 
tion of the pulp is occupied by the trunks of the nerves and by those 
of the bloodvessels, all of these special tissues being supported by a 
framework of myxomatous tissue, a modified connective tissue. 



132 



DEVELOPMENT OF THE JAWS AND TEETH. 



If sections of injected and properly stained pulps be viewed under 
a low magnifying power, it is seen that the arteries and nerves enter the 
pulp, and the veins leave it by several trunks. Arteries divide and 
subdivide until they terminate in a capillary network immediately 
beneath the odontoblastic layer. The nerves are medullated and non- 
medullated ; the former soon lose their medullary sheath, their ter- 

Fig. 76. 




Section of developing tooth of rat: a, bloodvessels entering the odontoblastic layer of cells from 

the pulp ; b, dentin. (Williams.) 



minals apparently ending in a network beneath the odontoblasts. The 
odontoblasts (Figs. 73 and 75) have the appearance of a thick, cellular 
boundary membrane. To make out the details of structure of the pulp 
a magnifying power of 400 diameters must be used. 

The Odontoblasts. — The boundary peripheral cells — the odonto- 
blasts — closely resemble columnar epithelium, having between the cells 
but a very small amount of intercellular substance (Fig. 75). During the 
period of development the presence of a capillary supply has been detected 



HISTOLOGY OF THE MATURE TEETH 



133 



in the odontoblastic layer (Fig. 76 and 61). 1 It is to be recalled 
that, no matter how close their resemblance to epithelial cells, odonto- 
blasts belong to the connective-tissue group. Epithelium never becomes 
connective tissue, nor can connective tissue ever become epithelium, 
although the contrary opinion has been held by some histologists. 
Under abnormal conditions, however, epithelial cells may and do pro- 
liferate in the spaces of connective tissue (see Carcinoma). 

The odontoblasts are large cylindrical cells which in the pulp of the 

Fig. 77. 




Pulp from the root of a molar of a man set. 40. Ground-section after V. Koch's petrifying method : 
OD, active odontoblasts; OD u resting odontoblasts, reminding of osteoblasts; P, fibrillse of 
the pulp; A, arteries ; V, vein ; N. nerve. Zeiss apochrom. X 250. (Rose.) 



young adult are closely massed together, the large nucleus occupying 
the pulpal extremity of the cell. This gives a pear-shaped appearance 
to cells whose bodies have shrunk slightly in preparing the pulp for 
sections. Each cell is seen to send one, and sometimes two, prolonga- 
tions of its substance into the dentin — Tomes' fibres. Between the 

1 J. L. Williams, Dental Cosmos, 1896. 



134 DEVELOPMENT OF THE J A WS AND TEETH. 

ends of the odontoblasts and the formed dentin a layer of transitional 
or partially calcified dentin may be seen. At later maturity the 
odontoblasts appear to have reached their physiological formative-limit 
— they become smaller (Fig. 77). Under abnormal conditions, how- 
ever the formative activity may continue until but a faint trace of a 
pulp-chamber remains. 

The Pulp-matrix. — In the child the stroma, the matrix of the pulp, 
appears to be made up of a loose myxomatous tissue, a structureless 
basis-substance traversed by bloodvessels and nerves ; it is irregularly 
supplied with large corpuscles, at first round, but which subsequently 
develop filamentous processes, each cell having two or, it may be, 
several, giving the cell a stellate appearance — L e., they are the cells of 
myxomatous tissue. In the body of the pulp the cells are irregularly 
arranged, their fibrillar processes forming a loose network. In the root 
or constricted portion of the pulp the cells appear to exhibit the effects 
of general compression and have a spindle-like form, and are arranged 
with their longitudinal axes parallel with the axis of the root. In 
the mature adult the cells lessen in volume, and the extent and number 
of their processes increase. Manipulation of such pulps will show that 
they have increased in toughness. To the naked eye they appear to 
have become more fibrous. Rose 1 has shown that these fibres do not 
yield gelatin upon boiling ; hence they must be regarded as the trans- 
formed processes of cells, and not connective-tissue fibres. 

Vascular System. — The arteries of the pulp soon lose almost 
entirely their muscular coat, and their external coat is reduced to an 
inconsiderable amount of fibrous connective tissue ; the veins remain 
for an unusual distance without a marked muscular coat. Before the 
disappearance in the arterial walls and after their reappearance in the 
walls of the veins the muscular coat is reduced to a layer of extreme 
thinness, so that histologically the walls of the smaller vessels of the 
pulp are made up of an endothelial coat, and probably an elastic lamina, 
an attenuated connective-tissue coat surrounded by the loose stroma- 
tissue of the pulp. This histological datum has great clinical signifi- 
cance (see Diseases of Pulp). 

The vascularity of the pulp decreases with age. " In young teeth 
there are a number of arterial trunks entering the apical foramen, 
which lessen in number as the passage lessens in size " (Black). Soon 
after the entrance of the arteries at the apical foramen they divide and 
subdivide into numberless branches, and finally into a capillary network 
(Fig. 78), most marked immediately beneath the odontoblasts ; the capil- 
laries empty into veinules — these into vein-trunks of relatively large size 
as compared with the arteries. These vessels pass out of the apical 

1 Dental Cosmos, 1893. 



THE CEMENTUM. 



135 



Fig. 78. 



foramen parallel with arteries and nerves. This anatomical arrange- 
ment of arteries, veins, and nerves, having passage through such a con- 
stricted orifice, is of clinical importance. 

The Nerves. — The nerves of the pulp, even upon entry to the 
organ, appear to be both medulla ted and 
non-medullated. Whether they belong to 
both cerebrospinal and sympathetic sys- 
tems is not made out ; nor is their phys- 
iological connection with the vessels of 
the pulp determined. The ultimate bun- 
dles of nerve-nbrillse appear to form an 
intricate plexus immediately beneath the 
odontoblasts. By the use of Golgi's stains 
Retzuis 1 demonstrated that in the mouse 
the finer nerve-fibres interlace about the 
bloodvessels, the nerve-trunks themselves 
following the direction of the bloodvessels. 
The terminal fibrillse of the nerves found 
their way between the odontoblasts, appar- 
ently terminating in knob-like extremi- 
ties between the odontoblasts and the den- 
tin, but showing no evidence of penetra- 
tion of the dentinal tubuli. No direct 
anatomical connection has been made out 
between the nerve-fibres and the odonto- 
blasts, although, as will be shown later, their physiological connection 
is evident. 




Point of the pulp of an incisor, in- 
jected with Beale's blue to show 
the bloodvessels. X 25. (Black.) 



THE CEMENTUM. 

The analogy between dentin and bone is made out with some dif- 
ficulty ; that between bone and cementum is evident — cementum is a 
modified bone. Examined in gross mass the cementum is seen to be 
deposited over the entire root and frequently slightly overlapping the 
extreme edge of the enamel at the neck of the tooth, this being the 
point at which the first-formed layers of cementum are laid down, the 
cementum over the apex of the root being that last formed. At the 
period accepted as the physical termination of tooth-formation the 
cementum is evenly disposed over the root of a tooth ; this is some 
time subsequent to the eruption of the teeth. Recalling that the 
development of cementum is a subperiosteal formation of bone, the 
growth of cementum continues at the sides, and particularly over the 
ends of the roots, pari passu with the decreasing thickness of the peri- 
1 Gustav Retzuis. See Catching' s Compend, 1896. 



136 DEVELOPMENT OF THE J A WS AND TEETH. 

cementum, so that at maturity the cementum is disposed as a sheath 
over the roots of the teeth, thinnest at their necks and thickest over the 
apices of the roots and also between the roots of bicuspids and molars 
at their junction. Examined under sufficient magnifying power the 
cellular elements of the cementum are not so easily made out as are 
those of bone ; but by careful search one may detect the irregular 
bodies of the cementoblasts, which have formed around them the trans- 
lucent substance of cementum and remain enclosed in their cement-bed 
as the cement-corpuscles. 

Although there is no decided appearance of lamination in the 
cementum, there is clearly some evidence of stratification, particularly 
about half-way down the sides of the roots. In a longitudinal section 
numerous fine lines may be seen at right angles to the lines of stratifica- 
tion of the cementum ; these are former Sharpey's fibres. In the 
growth of cementum, as of bone, the fibrous elements of the enclosing 
periosteum have their ends caught in the calcifying bone, and they 
undergo calcification. These lines represent, therefore, old points and 
the method of attachment of the pericementum. 

It has been noted occasionally that the dentinal tubuli appear to 
enter the cementum, although their usual mode of termination is in the 
irregular granular layer of Tomes underlying the cementum. There 
appears to be a mechanical element determining the regularity of forms 
of the dental elements ; that is, they assume their typical forms under 
a definite pressure, but when this is variable the histological forms are 
altered. The first-formed layers of dentin, both in crown and root, it will 
be recalled, are deposited not against a rigid matrix-wall, but against 
soft tissue — the inner w T all of the enamel-organ, or the epithelial root- 
sheath of Hertwig ; this, no doubt, accounts for the disposition exhibited 
by the dentin of these parts to assume irregular forms. 

THE PERICEMENTUM. 

The pericementum is a somewhat complex structure continuous with 
the general periosteum of the alveolar process ; it is also the periosteum 
lining the inner alveolar walls, is the formative structure of the cemen- 
tum of the teeth, and, in addition, is the analogue of a ligament, for it 
serves to bind the root of the tooth to its articular walls — L e., those 
of the alveolus. As will be shown later, it is the tactile organ of 
the tooth — the organ of localization. 1 

In general terms the pericementum is a fibrovascular, neural, cellular 
structure, all of whose tissues perform important functions. Viewed in 
its totality, the structure of the pericementum varies with age ; thickest 

1 The description of the pericementum is largely derived from G. V. Black's work 
upon the Periosteum and Peridental Membrane. 



THE PERICEMENTUM. 



137 



when root-formation is just complete, it becomes thinner with age, until 
in some individuals it is reduced to a lamina of extreme thinness. Its 
outline-study divides the pericementum into three portions : that adjoin- 
ing the necks of the teeth, that covering the apices of the roots, and the 
portion between them. 

At the necks of the teeth the pericementum, as stated, is continuous 
with the periosteum covering the external alveolar walls, continuous as 
regards its fibrous tissues and also by the bloodvessels and nerves of the 
part. The neck- edge of the cementum of the tooth (Fig. 79) being at 

Fig. 79. 




Portion of the side of a root of a tooth, the gum and alveolar dental membrane, and the edge of 
the bone of the alveolus. A band of fibres is seen passing over the surface of the alveolus and 
dividing, some passing upward into the gum, others passing more directly across to the ce- 
mentum. Numerous orifices of vessels cut across transversely are seen between the tooth and 
the bone. (Tomes.) 

a higher level than the edge of the alveolar process, the pericementum 
rises to a higher point than the true periosteum. The fibrous tissue of 
both pericementum and periosteum is continuous with the subepithelial 
fibrous tissue of the gums. The epithelial tissue of the gums has about 
the neck of each tooth a rounded margin which leaves between gum 
and tooth a V-shaped depression. It has been asserted that there are 
infoldings of the epithelial covering of the gum at this point, forming 
glands which have a mucoid secretion, the glands of Serres. Black, 
who termed this epithelial arrangement the gingival organ, 1 later deter- 

1 American System of Dentistry, vol. i. 



138 



DEVELOPMENT OF THE JAWS AND TEETH. 



mined that it was without the secretory function attributed to it. 1 As 
in the skin, the gum is arranged in vascular papillae beneath the epi- 
thelium ; these are covered with cuboidal epithelium overlaid by a thick, 
resistant covering of squamous epithelium. 

The Pericementum as a Ligament. — As a ligament joining the 
cementum to the walls of the alveolus, the pericementum has a definite 
arrangement of its fibrous elements. That portion of the pericementum 
extending beyond and upon a level with the periosteum reflected from 
the outer alveolar walls has, like the periosteum, bundles of fibrous con- 
nective tissue ascending toward the crown of the tooth (Fig. 79). This 
portion of the pericementum unites the pericementum of all of the 
adjoining teeth together with the alveolar periosteum in one continuous 
sheet of tissue (Fig. 80). At a higher point within the margins of the 

Fig. 80. 




Cross-section of the central and lateral incisors below (toward the crowns) the rim of the alveolar 
wall, or through the necks of the teeth, showing the tissues of the septum and of the gums ante- 
riorly: a, portion of central incisor; b, lateral incisor; c, pulp-chamber of lateral incisor; 
d, d, cementum of central incisor ; e, e, cementum of lateral ; /, fibres of the peridental mem- 
brane, extending from tooth to tooth continuously ; these are fixed in the cementum of each 
tooth, and form the tissue of the septum ; g, g, fibres of peridental membrane, which join with 
the coarse fibrous tissues of the gums ; h, h, epithelial covering of the gums,,;', J. (Black.) 



alveolus the fibrous tissue of the pericementum passes horizontally be- 
tween the root of the tooth and its alveolar wall, the fibres of this 
portion being the largest and strongest of any part of the ligament. 
At deeper points the fibres pass from the alveolar walls to points of 
the cementum farther distant from the alveolar margin, and the 
tissue is arranged in looser bundles. Around the apical portion of the 

1 Periosteum and Peridental Membrane. 



THE PERICEMENTUM. 139 

root the fibres of the pericementum radiate from the cementum to the 
alveolar wall. There is no evidence in the mature pericementum of 
an anatomical division of the tissue into a dental and an alveolar peri- 
osteum, although from the mode of formation of the structures and the 
character of tissue formed by the alveolar cells and the cemental cells 
such a division might be deemed rational. 

The fibres named are of white fibrous connective tissue and their 
arrangement such that the tooth is swung in its socket. " The oblique 
fibres protect the tissues of the apical space against the stress of mas- 
tication and the horizontal fibres maintain the tooth in position. " 

The fibres of the pericementum are attached to cementum and to 
the alveolar walls by large fibrous trunks, which split up into fasciculi 
of fibres in the body of the pericementum, the fine fibres interlacing 
with one another. Interspersed throughout the fibrous tissue of the 
pericementum are spindle-shaped connective-tissue cells — fibroblasts 
(cells from which fibres develop) ; they are numerous in the young, 
almost absent in the aged pericementum. 

The other cellular elements of the pericementum are cementoblasts, 
arranged in an irregular layer against the cementum, the fibrous bundles 
passing between them for attachment to the pericementum. On the 
alveolar side osteoblasts are found. Upon both sides multinucleated 
cells, osteoclasts and odonto- or cementoclasts, are found sparsely at 
irregular intervals. They are, no doubt, increased in number under 
some conditions, and at times almost entirely absent. 

Black describes peculiar cellular bodies occupying the meshes of the 
pericementum near the cementum. These have the appearance in sec- 
tion of glandular tissue cut across. The cells appear epithelial in char- 
acter. The author quoted suggested that these cells and collections of 
cells belonged to a lymphatic system but now believes them to be epi- 
thelial. Considering the mode of formation of the roots of teeth, it is 
more than possible that they are the remnants of the atrophied epi- 
thelial root-sheath of Hertwig. 

The Vessels of the Pericementum. — The pericementum is a highly 
vascular tissue deriving its blood-supply from three sources : one direct, 
two indirect. The direct supply is from the vessels at the apical space ; 
the indirect, by anastomosis with vessels of the alveolar periosteum 
which pass over the alveolar rim, and by anastomotic connections with 
the Haversian system of the bony alveolar walls. The vessels which 
enter the apical space send branches into the teeth supplying the pulp ; 
other branches pass down the pericementum, surrounded by the fibrous 
tissue of the membrane, and anastomose freely with the alveolar and 
the periosteal arteries. The vessels lie nearer to the alveolar than to 
the cemental walls. The cemental portions of the pericementum are 



140 DEVELOPMENT OF THE JAWS AND TEETH. 

freely channelled by a plexus of capillaries. The veins pursue the 
same course. 

The Nerves of the Pericementum. — The nerve-supply to the peri- 
cementum follows about the same course as that of the arteries. The 
nerves enter in bundles by way of the apical space ; some of them enter 
the pulp-chamber ; others run along the course of the pericementum, 
dividing and subdividing in their course. Other fibres enter by way of 
the Haversian canals of the alveolar walls, which split up and at the 
border of the pericementum form, with fibres from the gum, a fine gin- 
gival plexus. Black has observed in some cases the existence of 
Pacinian corpuscles as nerve-terminals of the pericemental nerves, but 
believes that the common mode of termination of the fibres is in fine 
naked filaments. 



CHAPTER VIII. 
THE SURGICAL ANATOMY OF THE TEETH. 

By the surgical anatomy of any part is meant a description of the 
structure and those relationships of the part which have a bearing direct 
or remote upon disease of such parts, and a study of those anatomical 
peculiarities which modify the nature, course, and treatment of such 
diseases. The surgical anatomy of the teeth, therefore, embraces not 
only a study of the structure of the teeth themselves, but also a con- 
sideration of the environment of the teeth and of all parts with which 
the teeth have direct anatomical and physiological relationship. 

The teeth are to be surveyed from two points of view, mechanical 
and physiological. Their office being that of the mechanical sub- 
division of the food, they are to be viewed as instruments built for that 
purpose. Like other parts of the body, their physical peculiarities and 
anatomical relations are the immediate factors to be considered in a 
study of the diseases affecting them. This includes a consideration of 
all features which are connected with the vital processes and reactions 
of the body, and a study of their nutrition and innervation, of their 
relationship with the lymphatic system, and of their associations by 
both continuity and contiguity. 

Beginning at the periphery and proceeding toward the centre several 
tissues are first to be examined. 

Dental Tissues. 

For a short period after their eruption the crowns of the teeth are 
covered by the structure called Nasmyth's membrane, representing, 
doubtless, in large part the remnant of the enamel-forming organ. As 
soon as the teeth are erupted this membrane is deprived of all nutrition, 
and is therefore a dead tissue — foreign to the body. It is soon worn off 
the crowns of the teeth by attrition, except in the deep sulci of the 
bicuspids and molars, and it remains for some time upon the enamel 
along the gum-margin, where it may later serve as a breeding-ground 
for micro-organisms. 

The tissue subjacent, the enamel, is an entirely extra-nutritional 
tissue, its source of nutrition disappearing at the termination of enamel- 
formation. Enamel, once formed, cannot be influenced by any nutri- 
tional changes in its substance ; it is a dead tissue. It is to be viewed, 

141 



142 



THE SURGICAL ANATOMY OF THE TEETH. 



first, as a structure designed to do mechanical work ; secondly, as to its 
reactions to its physical and chemical surroundings. Enamel is the 
hardest and most rigid tissue of the body. " If two blocks of equal 
size, one of enamel and one of dentin, be subjected to stress, it is 
seen that the enamel block crushes at a much lower stress than that 
of dentin, the latter being elastic, the former inelastic ; this appears 
to be true no matter in what axis the enamel is pressed upon ; but 
if a layer of material such as a mat of soft gold be interposed 
between the enamel and the instrument pressing upon it, its resistance 
is much increased." l If sections of the crowns of teeth be made, it 
will be seen that there is a mechanical arrangement of the enamel ele- 
ments and substance fitted to counteract the innate brittleness of the 
substance itself. First, the enamel surfaces are highly polished, so that 
there is a minimum of friction between opposing teeth ; any increase of 
roughness or any jaggedness of enamel robs the teeth of this advantage. 
Secondly, it will be noticed that nearly all of the enamel surfaces Avhich 
are brought into action during mastication receive mechanical support 
through an appropriate arrangement of enamel-masses. In the incisor 

Fig. 81. 





Architectural structure of au incisor. 



teeth, whose function is the cutting off of defined masses of food, they 
are primarily blades, which pass one another as the blades of shears, 
dividing substances which are placed between them. It will be readily 
seen that in this operation the upper incisors are subjected to greater 
stress than are the lower. The tendency is to break away the blade of 
the tooth (Fig. 81, bd) ; this is mechanically guarded against by the 
presence of two buttresses (6, b) merging with the angles of the cutting- 
blade, increasing in thickness as they descend to join a half girdle at 
the neck of the tooth (g). The outer faces of the blade are braced by 
three stanchions of enamel (s, s, s), one in the middle and one at each 
lateral edge. 

In the cuspid (Fig. 82), which may be regarded primarily as a pierc- 
ing instrument and secondarily as two cutting-blades set at an angle 
with one another, the cutting-blades are set with their edges at an obtuse 

1 G. V. Black, Dental Cosmos, 1895. 



DENTAL TISSUES. 



143 



angle, which forms the piercing-point. The edges have each a lateral 
buttress (6, b), uniting with a cervical half girdle, and, in addition, a 
thick buttress (6 3 ) descends from the point, merging into the girdle. 
Upon the outer face there are three stanchions (s, s, s), of which the 
middle one is most marked. In the bicuspid teeth, which, anatomically 

Fig. 82. 





Architectural structure of a cuspid. 

analyzed, are cuspids slightly modified and bound together, as indeed are 
also the molar teeth, in both molars and bicuspids then, appropriate 
architectural arrangement of the elements may also be observed. The 
upper bicuspids are seen to be two cuspids with their cusps or points 
upon opposite sides. It is seen that these two elements are bound 
together by two lateral girders or bands which join the lateral girders 
of the cuspid elements. A similar arrangement is found in the lower 
bicuspids (Fig. 83, g, g), although here the double cuspid character of 
the teeth is not so pronounced as in the upper. 

The upper molars (Fig. 84) are structurally composed of three cuspid 
elements bound together (g, g), although in the first and second molars 
a supplementary piece is found, which is weakly girdered to the second 
of the cuspid elements. It will be observed that this additional piece 
(c), whose junction with the tricuspid arrangement is marked by a sul- 
Fig. 83. Fig. 84. Fig. 85. 






Architectural elements of bicuspids and molars. 

cus, is an element of weakness. In the second molar the additional piece 
is smaller and not so well attached ; in the third molar it is usually absent. 

The lower molars (Fig. 85) are composed of four cuspid elements, 
the two outer and the two inner being bound together by an anterior 
and a posterior girder [g, g). Upon the first and third molars a disto- 
buccal supplementary piece (c) is girdered to the quadrangular mass. 

In all of the bicuspids and molars the cuspid character of each cusp 



144 THE SURGICAL ANATOMY OF THE TEETH. 

is well maintained in its individual buttresses. The buttresses of the 
lower incisors and cuspids are much less pronounced than in the upper 
incisors. The bicuspids and molars, the stress upon whose cuspid ele- 
ments is mainly lateral, have a buttress and girder arrangement to resist 
fracture through such a stress. 

It is evident that a tooth which has lost any portion of these sus- 
taining structures becomes mechanically weakened in proportion to the 
extent of the loss. If the lateral girders of a bicuspid or molar be lost 
through decay, or are cut through, the tendency to fracture of the parti- 
ally unbound cusps is much increased. If decay in an incisor involve 
the lateral girders of the tooth, the strength of the cutting-blade becomes 
correspondingly weakened. 

If sections of the several teeth be made and viewed under a low 
magnifying power, ir will be seen that the elements of w T hich enamel is 
composed have an arrangement admirably fitted to resist the stress to 
which any particular mass of enamel is subjected. If a mass of enamel 
be detached from a tooth, and attempts be made to cut it Avith steel 
instruments, it will be found that while the hardest steel fails to cut 
it, a chisel-edge may be made to break away portions of the tis- 
sue ; this occurs readily only when the tool-edge is applied in the direc- 
tion of the enamel-rods ; if applied at right angles to the enamel-rods, 
portions are broken away only with much difficulty, and, as a rule, 
the hardest of tool-steel fails to make any impression upon a perfectly 
polished enamel surface. Examining prepared sections of entire teeth, 
it will be seen that the enamel-rods are arranged with their longitud- 
inal axes in such positions that in the impact of mastication stress is 
received upon the ends of the rods in the lines of greatest resistance. 1 
Defects in the enamel, such as described under malformations of 
the teeth, have a direct and important surgical bearing. 
Enamel appears to differ widely as to its physical strength, 
and also in its degree of solubility in acids. As will be 
detailed under the head of caries of the enamel, fissures 
afford opportunities for the lodgement of food-debris, 
the nidus of lactic fermentation ; and, again, the calcic 
cementing-substance lying between the calcified globules 
of the enamel-rods is more soluble in lactic acid than 
are the globules ; hence enamel in which cementing- 
substance is in excess is less resistant. 

The enamel is thickest and in greatest amount where 

it receives the greatest stress, shading off until at the 

neck of the tooth it terminates in a feather-edge, whose 

outline is that of the gum-margin of the particular tooth, about one- 

1 See, later, Mechanical Arrangement, in this connection. 




SURGICAL ANATOMY OF THE DENTIN. 145 

sixteenth of an inch below which margin the enamel-edge is found, 
overlaid slightly by the thin edge of the cementum (Fig. 86). 

Surgical Anatomy of the Dentin. 

Dentin is the second hardest tissue of the body. The texture of 
this tissue changes, as does that of the other connective tissues, with age. 
In the young or immature dentin there is a greater ratio of organic 
matter than in the dentin of a middle-aged person. The increase of 
calcium salts, the inorganic constituents, has been shown by Black l not 
to be so great as was formerly believed. The average amount of cal- 
cium salts in teeth at the age of 11 years is found to be 62.26 per 
cent. ; at 53 years the percentage is 64.56. The average specific gravity 
at 11 years is 1.066, and at 63 years 2.109. While in the main the 
increase of specific gravity corresponds with the increase of calcium 
salts, it is not constant. Between the ages of twenty and forty years 
there appears to be a cessation in the increase of calcium salts. 

Dentin is an elastic substance : a cube of y-§ q inch side under 
a stress of 150 pounds is compressed 4 per cent, of its thickness, resum- 
ing its form after removal of the pressure. Under a pressure of 238 
pounds the cube is crushed. Clear and translucent dentin has a high 
crushing stress ; in opaque specimens it is much lower. An increase in 
the percentage of calcium salts diminishes the elasticity of dentin ; but 
the amount of crushing stress appears to be governed more by the con- 
dition of the organic matrix than by the percentage of calcium salts or 
the density. When the nutrition of the dentin is interfered with by sec- 
ondary deposits, or destroyed through death of the dental pulp, the 
dentin appears to diminish in strength, as seen in the abraded teeth 
of elderly persons. 

The average percentage of organic matter in dentin is 25.36 ; this 
diminishes as the density increases. Black believes that the condition 
of the organic matrix of the teeth has more to do with the strength of the 
teeth than have the density and specific gravity. The proportion of 
organic matter, as pointed out by Miller, 2 is not an exact measure of the 
hardness of the dentin, for many interglobular spaces and wide tubules 
may account for a high percentage of organic matter, and yet the dentin 
of the tooth be very dense. 

The dentin presents at least three distinct factors for consideration 
in studying diseases which affect it : first, the basis-material, the calcified 
matrix of the tissue ; secondly, the partially calcified tubes which 
surround the third factor, the vital protoplasmic filaments of the den- 

1 Dental Cosmos, 1895. The statements made relative to the physical properties of 
dentin are mainly from the same source. 

2 Micro-organisms of the Human Mouth. 

10 



146 THE SURGICAL ANATOMY OF THE TEETH. 

tin which penetrate its substance and traverse it from the periphery 
of the pulp to the periphery of the dentin. The calcified basis-sub- 
stance of dentin is soluble, as is the enamel of the teeth, in dilute acids, 
such as lactic acid, produced by the fermentation of carbohydrates. 
When subjected to the action of dilute acids it is changed from the 
material exhibiting the strength noted above into a mass of about the 
consistence of cartilage, or softer ; deprived of its calcium salts, it still 
retains its form. Different specimens of dentin exhibit different solu- 
bilities. The differences in the percentages of calcium salts and in 
density do not appear to be sufficient to explain differences of solubility. 
" The calcium salts appear to be present in the teeth and bony tissues 
in a combination represented by (PO 4 ) 6 Ca l0 CO 3 , or saturated calcium 
phosphate-carbonate, in a combination which corresponds with apatite, 
(PO 4 ) 6 Ca 10 Fl 2 , phosphate-fluorid of calcium." 1 

It is not known how this material is combined with the basis-sub- 
stance, the glue-giving substance of the dentin ; " whether it is a chemical 
precipitation, or whether there is a chemical union between the organic 
and inorganic constituents. In view of the mode of formation of calco- 
globulin, the basis of such tissues, it is probable that the latter con- 
dition exists. " We should expect to find dentin hard or soft according as 
this union is firm or unstable." 2 

The general dentin-substance is to be viewed as an interstitial sub- 
stance, as formed material which in itself necessarily plays a passive 
part in the disease-processes of dentin. It has been held that the den- 
tin undergoes retrogressive changes, particularly a decrease in the 
amount of calcium salts in the tissue, not due to the action of extrinsic 
causes. As a typical example of this alleged metamorphosis are given 
the changes occurring during pregnancy, when the dentin of the teeth has 
been said to suffer a resorption of calcium salts ; when a more favorable 
physical condition obtains, a re-deposition of calcic matter is said to 
occur, restoring the original density of the teeth. Black's analyses 
indicate that no such resorption and deposition occur. The basis of 
this belief was in the undoubted fact that during gestation the teeth of 
the mother suffer markedly from dental caries. 

The researches of the same observer showed that there is a greater 
variation in the density and specific gravity of the individual teeth of a 
denture than is found in the general average density of many persons. 

In line with the same line of reasoning which formulated the 
hypothesis of resorption and re-deposition of calcic matter should be 
mentioned the belief of histologists of the Heitzmann school in the 
possibility of dentin returning to its embryonic form ; no sufficient evi- 
dence having been adduced in support of such a belief, it must be set 

1 Hoppe-Seyler, quoted by Miller, Micro -organ isms of the Human Mouth. 2 Ibid. 






SURGICAL ANATOMY OF THE DENTIN. 147 

aside, for in addition there are numerous evidences that no such change 
ever occurs. 

Sections of teeth which have been subjected to the prolonged action 
of dilute acids show that the dentin immediately surrounding the pro- 
toplasmic filaments from the odontoblasts is more resistant to the 
action of the acids than the formed material of the dentin. Noting 
this comparative insolubility, this portion of the dentin (Neumann's 
sheaths) has been accepted as a partially calcified tissue. Regarding 
the general substance of the dentin as a fully calcified tissue and Neu- 
mann's sheaths as partially calcified and probably transitional tissue, it 
becomes a reasonable deduction that any future change in the density 
of the dentin or any increase in calcic deposits cannot extend be- 
yond the periphery of Neumann's sheaths. This agrees entirely with 
the condition found in the teeth of the aged, where the dentinal fibrillar 
are smaller and the lateral processes of Neumann's sheaths have almost 
disappeared. New dentin forms then at the expense of the size of the 
dentinal fibrillar. 

INTERGLOBULAR SPACES. 

If many specimens of dentin be examined, it will be noted that in 
some of them, notably in that portion of dentin underlying the cemen- 
tum, and less marked in the sub-enamel portion, the general striation 
produced by the presence of the dentinal tubuli is interrupted and 
broken into by irregular spaces — the granular layer of Tomes. In 
some specimens irregularly shaped areas are found widely distributed 
throughout the dentin, and it will be observed that the dentinal tubuli 
frequently traverse such spaces, being continuous upon both sides and 
through them. These are designated interglobular spaces ; during life 
they are filled with soft uncalcified material ; they represent areas of 
non-calcification, apparently an indication that the calcic salts of dentin 
are deposited in a previously formed soft matrix. 

DENTINAL FIBRILL^E. 

Occupying each dentinal tubule, and following its branches, those 
dichotomous branches beneath the enamel, are processes from the periph- 
eral cells, the odontoblasts of the pulp. Much speculation is still in- 
dulged in as to the precise nature of these processes. The most striking 
feature noted in connection with them is their variable sensitivity. When 
dentin denuded of enamel is brought in contact with acids, and frequently 
with sweet substances, a sensitivity is exhibited which varies in degree 
with individuals. The same result obtains when pressure is brought to 
bear upon such surfaces, or when applications of heat or cold are made to 
them. As will be noted later, these cells connected with the pulp, an 



148 THE SURGICAL ANATOMY OF THE TEETH. 

organ which has no sense of location, do not localize sensation ; the 
discomfort, pain, or anguish which may be induced by the contact 
of irritating substances is vaguely located in that branch of the di- 
vision of the fifth nerve involved. This sensitivity has led to the 
inference that these protoplasmic processes are in reality nerve-fila- 
ments ; this one feature supports such a belief; numerous other data 
contradict it. The processes have been observed as arising directly 
from the bodies of odontoblasts, but as yet no nerve-fibrils have 
been detected terminating in the odontoblasts. To regard the odonto- 
blasts as special nerve-terminals would be certainly not irrational, but 
until nerve-fibrils are discovered ending in the odontoblasts the question 
is sub judice. 

Retzuis observes l by the use of Golgi's stain that the nerve-fibrils 
of the pulp appear to penetrate between the odontoblasts and terminate 
between them and the dentin. The only certain datum is, that these 
fibrillar or processes have the power of receiving and transmitting sensa- 
tion equivalent to, if not identical with, that possessed by nervous tis- 
sues. It is certain also that they are portions of the dentin-building 
cells, and probably possess in some degree the same constructive 
function. 

The Pulp and Its Chambers. 

The pulps of the teeth are closely bounded at all parts by dentinal 
walls ; the chamber of lodgement represents, therefore, the precise size 
and form of the enclosed pulp. The pulp-chambers have forms which 
correspond quite closely, but not entirely, with the forms of the partic- 
ular teeth. If sections be made in three diameters of the teeth, these 
correspondences in form are readily seen, and divergences are observed 
which are of much surgical interest. Nothing but general rules can be 
given as to these variations from general types, as the variations may 
assume very diverse characters (see Figs. 103-113). The pulp is ana- 
tomically divided into two parts : that occupying the crown of the tooth 
is called the body of the pulp, and that occupying the roots the radicular 
portion or portions. The prolongations from the body of the pulp 
which correspond with the positions of the cusps are called the horns 
or cornua of the pulp. It will be observed in many specimens that the 
cornua of pulps, notably of the upper lateral incisors and upper first 
bicuspids, very frequently extend as sharp and unduly long projections. 
It will also be seen by a reference to Figs. 87-102 that the distance 
from the exterior walls of the teeth to the pulp-chambers is much less 
at the necks of the teeth than at other parts. This is particularly notable 
in connection with the upper molars ; the distance from the exterior to 
the pulp-chamber at the cervico-mesio-buccal angle is frequently very 

1 Catching' s Compend, 1896. 



THE PULP AND ITS CHAMBERS. 



149 



slight. Another peculiarity of tolerable constancy is the nearness of 
the body of the pulp to the cervico-distal portion of the lower molars. 



Fig. 87. 



Fig. 88. 





Fig. 89. 



Fig. 90. 





Fig. 91. 



Fig. 92. 






Fig. 93. 



Fig. 94. 






Sections of upper teeth, showing shapes of pulp-chambers and their positions. Figs. 92 and 93, 
first figures, represent sections through the buccal roots of upper molars ; second figures are 
sections through the palatal root and portion of the anterior buccal roots. 

While, as a rule, the external configuration of a tooth is a fair guide to 
the shape of the pulp-chamber, variations are so common that proximity 
to the pulp in a carious cavity is more accurately determined by elicit- 



150 



THE SURGICAL ANATOMY OF THE TEETH. 



ing subjective symptoms than by the objective evidence of the depth of 
the cavity. 

Figs. 103-113 exhibit formalin-gelatin casts of pulp-chambers, 1 
showing the great irregularities of form which pulp-chambers may 
assume, and yet give no external evidence of such irregularities. 
Figs. 107-110 show the outline-forms of the crown portions or bodies 
of dental pulps. 

Fig. 95. Fig. 96. Fig. 97. 







Fig. 98. 



Fig. 99. 



Fig. 100. 







Ftg. 101. 



Fig. 102. 





Sections of lower teeth, showing shapes of pulp-chambers and their positions. Fig. 101 shows a 
section through the anterior root of a second molar ; an antero-postero-longitudinal section 
would resemble Fig. 100 

The pulp-chamber decreases in size with age, so that in some cases it 
is almost obliterated to the end of the root. Secondary deposits (see 
Secondary Dentin) may fill portions of the cavity and reduce its size in 
almost any direction. As will be shown, these deposits may occupy 
the greater bulk of the pulp, and yet the pulp-chamber remain of 
normal size. 

1 W. H. Richards, Dental Cosmos, 1896. 



THE PULP AND ITS CHAMBERS. 



151 



PULP AND CHAMBERS OF TEMPORARY TEETH. 

The same rule as to the general size and configuration of the pulp- 
chamber noted in connection with the permanent teeth holds good in 

Fig. 103. 




Fig. 104. 




the temporary teeth, with this difference, however : it is frequently 
found that the relative size of the pulp-chambers is greater than in the 



152 



THE SURGICAL ANATOMY OF THE TEETH. 



permanent teeth, so that exposure of the pulp results soon after caries 
has invaded the dentin. The radicular portions of the pulp-chambers 

Fig. 105. 







Fig. 106. 




of the temporary teeth when fully developed are frequently much 
attenuated. 



THE PULP AND ITS CHAMBERS. 



153 



The pulp of the tooth contains several factors of surgical interest : 
first, its vascular, next its neural supply. The pulp is not provided with 

Fig. 107. 




Fig. 108. 




lymphatics, so that effusions which occur in its substance must be taken 
up by the veins or remain in the stroma of the pulp. The third ele- 



154 



THE SURGICAL ANATOMY OF THE TEETH. 



ment of interest is found in the layer of odontoblasts, eells which 
possess a persistent formative and sensory function, and next the 



Fig. 109. 




Fig. 110. 



J' 




^^^r^P^^^B 








^m^~^- ... :<•! 








■■ ■ 
























1^ «■ 








t*£* 








■ ■ 








%- 


J* 


■ 
v. 


H^9^ ^ ^fifl 


r*N». 


- 




. 


. 


"■ 












y 


%$' -'* 


1 





stroma of the pulp, its framework. The formative cells of the pulp, 
as will be noted later, are responsive to stimulation, and when stimu- 



THE PULP AND EPS CHAMBERS. 



155 



lated exhibit an exaltation of function expressed in heightened sensi- 
tivity and formative activity. These cells, arranged in a layer of toler- 




Fig. 112. 




able regularity, one cell deep, are by mutual pressure forced into an ar- 
rangement resembling that of cylindrical epithelium, but having a slight 



156 



THE SURGICAL ANATOMY OF THE TEETH. 



space between adjoining cells. The odontoblasts appear to abut directly 
with the dentin, one or more protoplasmic processes passing from each 
cell into dentinal tubuli. With increasing age the odontoblasts appear 
to suffer atrophic changes (Fig. 76) (Rose). Beneath the odonto- 
blasts and penetrating the odontoblastic layer for some depth in the 
developing teeth is a loop- work arrangement of capillaries (Williams). 

Fig. 1 13. 




The arterial supply to the pulp enters the apex of the root through 
several branches, which subdivide and appear to lose their muscular 
coat at an early period of subdivision. The capillary distribution is, 
as stated, in a loop arrangement beneath the odontoblastic layer. The 
capillaries join veins of very large size, in which the middle coat ap- 
pears to be absent for a long distance. It is evident, then, that should 
pulp arteries and veins lacking this muscular coat be subjected to in- 
creased intravascular tension, danger of injury to their walls is imminent, 
and occurs in hypersemic and inflammatory conditions. 

The nerves, entering by way of the apical foramen, are both medul- 
lated and non-medullated ; in the peripheral distribution all of the fibres 
are non-medullated. Whether the non-medullated fibres are purely vaso- 
motor, and the medullated the sensory fibres, is not determined. A 
point of much surgical interest relates with the sensory function of the 
pulp nerves. As emphasized by Black, 1 the pulp is a truly internal 
organ, and, like many other internal organs, it has no sense of location 

1 American System of Dentistry, vol. i. 



CEMENTUM AND PERICEMENTUM. 157 

— i. e., it is not the touch-organ of the tooth, so that when subjected to 
irritation these nerves react as do the nerves of other typical internal 
organs — reflect the sensation to some other branch of the same nerve. 
The classical illustration of this phenomenon is the pain of certain 
hip-joint diseases : the pain is not felt at the disease-seat, but upon the 
inner side of the knee ; the pains of hepatic disorders are referred to 
the right shoulder-blade ; those of inflammation of the eye-curtain, the 
iris, to the brow. 1 This is a fact of great clinical importance in den- 
tistry, viz., pains due to disorders of the pulp are not accurately located, 
but are referred to distant points. The pulp nerves are, however, sin- 
gularly intolerant of pressure, responding in painful paroxysms to any 
pressure, internal or external. 

The stroma of the pulp has a distinct surgical interest. It is to be 
recalled that originally the pulp consisted of a mass of undifferentiated 
mesoblastic cells in a structureless basis-substance. Later, some of 
these cells become differentiated into dentin-forming cells ; the dentin 
is finally deposited in a finely fibrillated stroma of fine gelatin-yielding 
fibres. At maturity the cells of the pulp are of a myxomatous type, 
contained in an apparently structureless matrix ; of polygonal form in the 
crown of the pulp, these cells show a semblance to a fibrillated arrange- 
ment in the radicular portion of the pulp. It has been shown by Rose 2 
that these cells and their processes are not ordinary connective-tissue cells ; 
they do not yield gelatin upon boiling. As the pulp increases with age 
the bodies of the cells grow smaller and their fibrillar processes become 
more marked, until in an old tooth an appearance of fibrous tissue is 
seen. The matrix-cells are of pathological interest from the fact that 
they appear, under some conditions, to assume the formative office of 
odontoblasts, deposits of dentin occurring in the pulp-substance. The 

changes which occur with age in the tissue of the pulp may be likened 
to sclerosis. 

Cementum and Pericementum. 

At the apex of the root the arterial and neural supply to the interior 
of the tooth is continuous with the same structures to the external vital 
structures of the tooth, viz., the pericementum and the cementum. 

The pericementum is the touch-organ of the tooth, the nerves of 
which possess the sense of location. The pericementum is the mutual 
periosteum of the cementum of the tooth and of the enclosing alveolar 
wall ; reflected over the external alveolar wall this periosteum becomes 
continuous with the general maxillary periosteum. In addition, the 
pericementum is the ligament binding the tooth in its articular (the 
alveolar) walls. As a periosteum it is a source of nutrition to the 

1 Black, Ibid. - Dental Cosmos, vol. xxxv. 



158 THE SURGICAL ANATOMY OF THE TEETH. 

cementum and to portions of the alveolar walls, so that interference 
with its vascular supply is followed by malnutrition of these tissues, 
the effects being governed by the extent of the interference (see General 
Pathology). As a ligamentous tissue, its fibres, as shown by Black, 1 
have a peculiar arrangement. The bundles of fibrous connective tissue 
which pass from the alveolar walls to the cementum are oblique in their 
general direction, the fibres passing from a point nearer the margin of 
the alveolus to a deeper portion of the root. 

The nerves of the pericementum are accustomed to a degree of press- 
ure represented in the amount of force necessary to crush the particles 
of food ; if subjected to a greater stress, they rebel. 2 Similarly, if 
their functional activity is exalted in hyperaemic disturbances, they 
become cognizant of very slight pressures and react more strongly. It 
is to be remembered, however, that the teeth rarely receive direct stress, 
the movements of the teeth in mastication being more of a rotary and 
laterally moving character, than perpendicular. 

The elasticity of the pericementum is to be regarded also as an adju- 
vant to the local circulation ; by its movements the blood is pumped 
through the vessels of the part. This fact becomes important when it 
is recognized that in some dentures increasing age is accompanied by a 
lessening of the volume and elasticity of the pericementum. 

The power of recovery of the pericementum after injury appears to 
be very great. It will be observed that the pericementum has two 
sources of vascularity : one from the apical vessels, that from which the 
vascular supply of the pulp arises ; the other, an anastomotic circula- 
tion from the alveolar walls, directly and indirectly from the general 
alveolar periosteum. When the apical vessel-trunks have been obliter- 
ated as the result of disease the pericementum receives from the anasto- 
motic circulation a blood-supply practically sufficient. 

The cementum maintains its vitality so long as the pericementum is 
intact ; in the condition just mentioned it is evident that the apical 
portion of the cementum dies, or is at best very ill nourished. The 
layer of cementoblasts (osteogenetic cells) retain their function so long 
as the pericementum is intact, and under varied conditions exert their 
constructive function in an irregular manner (see Hypercementosis). 

Surgical Relations of the Teeth. 

The several groups of teeth — incisors, cuspids, bicuspids, and molars 
— all have surgical relationships differing in each jaw and in each dental 
group. 

1 Periosteum and Peridental Membrane. 2 Black, Dental Cosmo*, 1895. 



SURGICAL RELATIONS OF THE TEETH. 



159 



Fig. 114. 



THE LOWER DENTURE. 

Incisors. — The lower central incisors, as well as the lateral incisors 
and cuspids, receive their main vascular supply from the continuation 
of the inferior dental artery, the passageway of which is not so well 
marked a channel as in the portion of the jaw posterior to the mental 
foramen. The neural supply is from the inferior dental nerve, which 
returns through the mental foramen recurrent branches, which pass to 
the muscles about the mouth. This association of nerves is made clini- 
cally evident in many cases where dental irritation of these teeth causes 
painful symptoms referred to the soft parts about the mouth. 

Direct surgical interest as to the lower incisors associates with the 
relations of the apices of the roots of these teeth with their bony sur- 
roundings. A section through the symphysis of the jaw will show the 
bone to be very dense at the site of the section. Sections passing 
through the axes of the central incisors 
will show that beneath the apices of 
the roots is a mass of irregularly chan- 
nelled cancellated bone, bounded by 
an inner and an outer layer of corti- 
cal bone, the inner or lingual layer 
being much more dense than the outer 
(Fig. 114). As a rule, the nearest 
point of approach of the root of the 
tooth to the surface is upon the outer 
or labial side, where but a thin layer 
of cortical bone may overlie the apex 
of the root in the incisor fossa. On the 
lateral incisors the layer of bone is 
usually a little thicker, and thicker yet 
over the apex of the root of the cus- 
pid, provided the root be not abnor- 
mally short. In all of these teeth, 
and, as will be shown later, in all of A lon « itllrti nai section through a lower 

, , central incisor and its neighboring parts. 

the lower teeth, the minimum thick- 
ness of dense cortical bone is not over the apices of the roots, as in 
the upper jaw, but at points about midway between the necks of the 
teeth and the root-apices. This will explain why abscess upon the roots 
of the lower teeth rarely discharge over the apices of the roots of the 
teeth. 

Occasionally the roots of the lower incisors are overlaid labially by 
an unusually dense layer of cortical bone ; this fact, taken in connec- 
tion with the observation that at the submental portion of the jaw, 




160 



THE SURGICAL ANATOMY OF THE TEETH. 



immediately beneath these roots, is a relatively thin layer of cortical 
bone, furnishes the solution as to why an abscess upon these teeth may 
open beneath the chin. 

Bicuspids. — The bone overlying the roots of the bicuspids at their 
lingual aspects is sometimes relatively thin, as it forms the wall of the 
sublingual fossae. Upon the labial face the cortical bone is in greater 
amount, although thin. The spaces between the first and second bicus- 
pids usually marks a site immediately above the mental foramen, al- 
though the opening may be posterior, or in some cases anterior, to the 
position named. If the roots of the bicuspids are abnormally long, 
they may encroach upon the area of the foramen. This occurs most 
frequently with the root of the second bicuspid, affections of which 
tooth may cause diffused pain, apparently owing to the proximity of the 
root-apex to the nerve-trunk at the foramen. 

Molars. — In studying the surgical and anatomical relations of the 
lower molars, the anatomical subdivision of the lower jaw becomes most 
apparent from every point of view. It is anatomically and clinically 
divided into an alveolar portion and the maxillary portion proper, the 



Fig. 115. 







Showing the relations of the roots of the lower third molar with the cavities of the mouth and 
neck, and with the external bony wall : A, cavity of mouth separated from B, the cavity of the 
neck, by the mylohyoid muscles ; C\ base of the coronoid process ; D, muscles of the cheek. 

alveolar portion — that portion in which the teeth are embedded and 
which surrounds them — being set upon and inside the body of the 
bone. The fact that the alveolar portion is set inside the body division 



SURGICAL RELATIONS OF THE TEETH. 



161 



Fig. 116. 



is not so apparent in the anterior portion of the jaw, although it will 
be readily seen that the dental arch has a smaller radius than the max- 
illary arch ; but at its extreme posterior portion the relationship is most 
evident, where the outer edge of the coronoid process is some distance 
external to the buccal faces of the lower third molar (Figs. 115 and 116). 
It is with this superimposed and inserted mass of bone that dental dis- 
eases are almost entirely concerned. According to Allen, 1 " all diseases 
affecting this portion of the bone are to be regarded as dental." 

The boundaries of the molar portion of the alveolar bone are to be 
clearly kept in mind (Fig. 116). If sawn away from the body of the bone, 
it will have the form of an irregular 
quadrangular pyramid, the base of 
which represents the section between 
the first molar and the second bicuspid, 
one side the alveolar margins about 
the molars, another the buccal por- 
tion of the bone adjoining the exter- 
nal oblique line, its inner side, the 
alveolar portion, having the inter- 
nal oblique line (mylohyoid ridge) 
as a margin ; its remaining side, 
the bone, overlying the inferior 
dental canal. These four sides 
merge into a point beyond the inner 
and outer divisions of the base of 
the coronoid process. In position 
the pyramid lying upon one side, 
that forming the roof of the inferior 
dental canal, is seen to have grad- 
ually altering anatomical relations Showing the relative position of the posterior 

advancing toward the apex of the portion of the alveolar bone (the dentale) 

° r with the maxilla proper. 

pyramid. Viewed upon the inside, 

one edge of the pyramid lies along the boundary line, the internal oblique 
line, the line of insertion of the mylohyoid muscle which divides the 
cavity of the mouth from the cavity of the neck ; with its covering of mu- 
cous membrane the muscle forms the greater portion of the floor of the 
mouth. As this line approaches the surface of the mouth progressively 
to immediately back of the third molar, its relations, and therefore the 
relations of the cavity of the neck to the roots of the teeth, also change. 
So that while the roots of the first molar are rarely deeper than the 
mylohyoid ridge, the second and more frequently the third molar roots 
may pass to a greater depth (Fig. 117). It will also be observed that 

1 Harrison Allen. Human Anatomy. 
11 




162 



THE SURGICAL ANATOMY OF THE TEETH. 



the smaller size of the alveolar arch, as compared with the mandibular 
arch, causes the molar portion of the alveolar bone to project bodily 
into the cavity of the mouth, so that a vertical line passed through the 



Fig. 117. 




Section of the molar teeth and corresponding portion of the inferior maxilla; the dotted line 
represents the position of the mylohyoid ridge, the open space beneath the inferior dental canal. 

vertical axis of the third molar would fall directly into the cavity of 
the neck without passing through the body of the bone (see Fig. 115). 
This relationship of parts makes the thinnest portion of bone over- 
lying the roots of molars at the apex of the distal root of the third 
molar. A drill passed through the frequently thin covering of cor- 
tical bone at this point emerges almost exactly in the groove lodging 
the mylohyoid branches of the inferior maxillary nerves and arteries. 
The root may terminate at a point some distance behind the anterior 
pillar of the fauces. Upon the external or buccal face of the bone it 
will be seen that the position of the third molar is at times some dis- 
tance posterior to the outer branch of the coronoid process, the con- 
tinuation of the external oblique line, so that a greater distance sepa- 
rates the roots of the second and third molars from the external surface 
of the bone than with any of the teeth of a denture. Abscess upon the 
roots of particularly the lower third molar, therefore, finds the path of 
least resistance as to pus-exit, first, by destroying the pericementum of 
the tooth and finding exit at the gum-margin, or, if the outer alveolar 
plate is not entirely walled in by the base of the coronoid process, 
through the alveolar process near the gum-margin (Fig. 115). An 
abscess may, by penetrating the lingual alveolar wall, open far back 



SURGICAL RELATIONS OF THE TEETH. 163 

in the mouth, if the roots of the tooth are not deeper than the mylo- 
hyoid ridge ; if the roots do penetrate beyond this ridge, it may open 
in the neck in the submaxillary triangle. 

In some cases the roots of the second and third molars may immedi- 
ately overlie the inferior dental canal, instead of being slightly inward, 
and the tissue intervening between the apices of the molar roots and the 
canal may consist of the very thin layer of perforated cortical bone 
which forms the roof of the canal. In some cases a molar root may be 
so deeply embedded as to encroach upon the canal, lessening its lumen 
and causing more or less compression of the inferior dental vessels and 
nerves. Pressure from such sources is, no doubt, the cause of obstinate 
maxillary neuralgias, which would be greatly exaggerated in disease- 
conditions about the pericementum, accompanied by inflammation or 
even hyperemia. In impacted third molars the pressure of some part 
of the tooth may cause great distortion of the course of the canal 
(see Chapter X.). The anatomical relations of the third lower molars 
are such that apical abscess upon them will have tardy vent, or else open 
in unusual situation. 

The blood-supply to the inferior maxilla through the inferior dental 
artery — large single trunks which traverse the bone longitudinally upon 
both sides — may be seriously impeded or checked by pressure upon the 
trunk as it enters or shortly after its entry to the canal, and thus, necro- 
sis of half the maxilla is a probable danger. In many cases, however, 
where the inferior dental vessels have been obliterated upon one side 
necrosis does not occur, the anastomosis of the facial artery with the 
dental about the mental foramen continuing sufficient circulation to 
maintain vitality. 

THE UPPER DENTURE. 

As in the lower jaw, the line of the symphysis, a thickened plane 
of bone, is an impediment to the extension of disease from either 
side. The demarcation between alveolar and maxillary portions is as 
clearly defined as in the lower jaw. In general terms, at the period 
of maturity a plane passing through the floor of the antrum and be- 
neath the floor of the nose divides the alveolar from the maxillary 
bone. As a rule, this plane would also rest upon about the height of 
the maxillary vault. In general character and in both vascular and 
neural supplies the upper jaw presents features differing from those 
in the lower jaw. 

The alveolar bone is formed, as in the lower jaw, of two layers 
of cortical bone, between which lies cancellated bone, chambered by 
the several alveoli for the roots of the teeth. Of these two plates, 
the outer is the thinner, and, unlike the outer alveolar boundary of the 



164 



THE SURGICAL ANATOMY OF THE TEETH 



lower jaw, is of nearly uniform thickness over the roots of all the 
teeth (Fig. 118). As in the lower jaw, a greater thickness of bone 



Fig. 118. 




Section of an upper incisor tooth, its attachments, and anatomical relations. 

overlies the roots at their lingual aspects. Differences as to the depth 
of the alveolar process are more apparent in the upper than in the lower 
jaw, measured, first, by the height of the dental vault, and, next, by 
the distance from the occlusal edges of the teeth to the reflection of the 
mucous membrane from the cheek to the gums. The apices of the roots 
of the several teeth in the upper as well as in the lower jaw are usu- 
ally about one-eighth of an inch or more above the line of reflection of 
the mucous membrane. The common vascular trunk from which the 
upper teeth derive their arterial supply is a short branch that divides 
into an alveolar portion which enters the posterior wall of the antrum ; 
running in the muco-periosteum of that sinus, it subdivides into numer- 
ous branches, some of which enter the alveolar portion of the bone as 
posterior dental arteries supplying the molar and bicuspid teeth. The 
posterior buccal portion of the alveolar walls, with the overlying gum- 
tissue, are supplied from the same source. The palatal portion of the 
alveolar process is supplied by a separate arterial trunk, the descending 
palatine, which emerges upon the palate at the posterior palatine fora- 
men, running forward thence to anastomose with the terminal branches 
of another small division of the internal maxillary artery, the naso- 
palatine, at the incisive foramen. The anterior teeth receive their vas- 
cular supply from the second branch of the common arterial trunk, 
viz., the infra-orbital artery. As this artery runs in the infra-orbital 
canal, it gives off descending branches which penetrate the antrum ; 
running under its muco-periosteum, it supplies the anterior portion of 
the sinus and branches penetrate the bone supplying the anterior teeth, 
anastomosing freely with the posterior dental arteries. 



SURGICAL RELATIONS OF THE TEETH. 165 

Disease, effusions, etc., may occlude the external alveolar arterial 
supply and cause necrosis of the dependent plate of bone, and yet the 
vascular supply of the internal alveolar plate remains intact. Again, the 
external alveolar bone overlying the anterior teeth may suffer occlusion 
of its circulation without affecting the posterior external alveolar blood- 
supply. This will account for the frequently limited character of 
necrosis of the upper alveolar bone, as compared with necrosis occur- 
ring in the lower jaw, and will serve to explain the forms of sequestra 
in certain cases. 

The neural supply to the upper teeth, derived from the superior 
maxillary division of the trigeminus, corresponds almost exactly with 
their arterial supply. The complex character of the anastomoses of 
the dental nerves will explain in some measure the varied character 
and indefinite location of pain of dental source in the upper jaw. 

Central Incisors. — The surgical relations of the roots of the central 
incisors are associated with the floor of the nose. Recognizing the 
bony floor of the nose as a common surface, with the plane of bone 
forming the hard palate, and the teeth-bearing bone as an arch-shaped 
rampart set upon this plane, it will be seen in the . majority of cases 
that the roots of the central incisors do not extend deeper than the base 
of the alveolar bone : but in rare cases their roots may impinge upon 
the bony floor of the nose, and a very thin layer composed of peri- 
cementum, bone, and muco-periosteum, may separate the apices of the 
roots from the floor of the nose. 

In some cases the outer alveolar plate overlying the apices of the 
roots may be very dense and comparatively thick ; and the palatal 
alveolar plate be thin, and furnish the line of least resistance to pus- 
collections. This may also be true of the lateral incisor ; the principal 
surgical interest of which, however, lies in the common and abrupt 
curvature of its root-apex, usually pointing away from the median line. 
It is of interest to note that this tooth is occasionally not found. 
Whether the lack of development arises from no cord ever being given 
off for it, or whether the tooth-follicle at some very early stage suffered 
atrophic changes, is not precisely known ; it is probable, however, that 
no follicle has been formed. 

Cuspids. — The surgical interest as to the cuspid teeth is, first, in 
their very deep implantation, in many cases their roots extending 
beyond the nasal floor, but to its outward side ; and, next, in the 
unusually compact character of the bone overlying their roots. Very 
frequently the bone overlying the apex of the root is of extreme thin- 
ness. 

Bicuspids. — The first bicuspid is chiefly notable for its two roots, 
labial and lingual. When these roots are divergent, which as a rule are 



166 



THE SURGICAL ANATOMY OF THE TEETH. 



convergent, the palatal root may be overlaid by only a thin layer of 
tissues. As with the molars, disease may attack but one root alone. 
With the second bicuspid an additional anatomical relation of surgical 
interest may be found. The root of this tooth may underlie the floor 
of the anterior portion of the maxillary sinus, although this relationship 
is not so common as with the next tooth in the dental series. It is to 
be remembered, as shown by Cryer, 1 that the cavity of the antrum 
becomes larger with age ; and while in the young adult the roots of all 
of the posterior teeth may be separated from the floor of the antrum by 
a considerable thickness of bone, progressive resorption with the con- 
sequent enlargement of the antral cavity may carry the floor of the 
latter not only down to, but in some cases beyond the apices of the 
roots of the teeth (Fig. 119). 



Fig. 119. 



0ms4 




1st M 
Oms, opening maxillary sinus ; 1st M, first molar. (Cryer.) 



Oins 



It will be observed that the true maxilla begins at the situation of 
the first molar, to extend outward far beyond the outer alveolar wall as 
an enormous process, the malar process, which is but a shell of bone, 
forming the greater portion of the outer wall of the antrum. While 
with the first molar usually only the palatal and disto-buccal roots 
underlie the antrum, the projection of the malar process carries the 
boundary of the antrum outwardly beyond all of the roots of the 
second and third molars. Upon lifting the lip of the living subject the 
1 "Studies of the Maxillary Bones," Dental Cosmos, Jan., 1896. 



THE TEETH AS MECHANICAL APPLIANCES. 167 

projection of the malar process is evident, its anterior edge overlying 
the first molar tooth. The line of the floor of the antrum usually lies 
about a quarter of an inch above the reflection of the mucous membrane 
from the cheek to the gum, and if a sharp drill be passed backward, 
upward, and inward from the reflection line above any of the molars, 
the antrum is readily penetrated. It will be seen that the anatomical 
relations of the roots of the molar teeth to the floor of the antrum, 
particularly in mature and elderly persons, are such that disease of the 
apical pericementum is necessarily followed by involvement of the tis- 
sues of the floor of the antrum. Moreover, extraction of teeth in some 
cases would be inevitably accompanied by fracture of the bony floor. 

The apex of the palatal root of the second molar lies in close prox- 
imity to the groove at the palatal base of the alveolar process, which 
accommodates the posterior palatine artery, so that slipping of an 
elevator in extraction might cause injury to this artery. The tuber- 
osity of the palatal process which lodges the roots of the third molar is 
a loosely cancellated knob of bone, having but weak boundary walls. 
At the base of its palatal portion lies the posterior palatine foramen. 
The frail boundary walls have been broken in attempts at extraction of 
this tooth, producing fracture of the condyloid process. Occasionally 
the excavation of the antrum extends far into this tuberosity, and 
forcible attempts at extraction of a conical molar have resulted in driv- 
ing the tooth bodily into the antrum. 

The Teeth as Mechanical Appliances. 

Having studied the physiological aspects of the teeth, they are to be 
surveyed as mechanical implements in which derangements of the 
primary mechanical design are followed by morbid alteration in dental 
physiology. 

The teeth, as mechanical instruments, are divided into four well- 
recognized anatomical classes : incisors, cuspids, bicuspids, and molars ; 
each group, and indeed each member of each group, is of mechanical 
design and position for a definite office. According to the form and 
position of a tooth, it is fitted to receive and resist stress applied to it. 
Stress in excess of this amount, or received from an abnormal direction, 
is to be regarded as a menace to the integrity of the tooth. The 
particular pathological interest in an excess or irregularity of stress lies 
in the response of the vital parts of the tooth implicated. The tissue 
or structure mainly concerned in the vital reactions of the teeth toward 
mechanical overwork, and, contrawise, toward disuse of the teeth, is the 
pericementum. 

The effects of overuse and of disuse will be discussed in detail in the 
section dealing with diseases of the pericementum. 



168 



THE SURGICAL ANATOMY OF THE TEETH. 



THE UPPER DENTURE. 

Incisors. — The broad cutting-blade of the central incisors receives 
a stress which tends to force it directly outward. In the normal den- 
ture this stress ceases as soon as the posterior teeth are brought into 
occlusion. The length of time the stress is in operation depends upon 
the extent to which the upper teeth overlap the lower ; if the overbite 
be great, the stress is proportionately increased. The roots of these teeth 
have as a mechanical provision against the stress a sectional form 
resembling a scalene triangle having much rounded angles, whose base 
is parallel with the edge of the cutting-blade, offering a broad surface 
of resistance. The tendency of the force of mastication, incision in 
this case, tending to drive the teeth away from the median line, the base 
of the triangle is placed at an angle with a plane transverse and at a 
right angle with the symphysis (Fig. 121). In the lateral incisors the 
same provision is observed as to the arrangement of the base of the 
section triangle of the root, which is decidedly more scalene (Fig. 122). 
While it would be apparently more in harmony with anatomical 
design that the length of the root should correspond with the amount 
of stress involved, so that teeth having a long overbite should have long 
roots, no such rule is observable, for it is frequently seen that teeth 
having broad and long cutting-blades have very short roots ; but, as a 
rule, the broad and long cutting-blade is associated with a root section 
triangle having a broad base. 

The Cuspids. — To appreciate the mechanical design of the cuspid 

Fig. 120. 




Side view of the cranium of a tiger, with the mouth, slightly opened to show the relative position 

of the great canines. (Tomes.) 

tooth, it must be studied as it occurs in its typical form, as the canine 
tooth of the carnivora. In these animals the enormously developed canine 
is formed to serve as a weapon of defence and offence, being provided with 
a very extensive and deep implantation to insure strength and firmness ; 
this characteristic is a constant associate of the true canine. In the preda- 



THE TEETH AS MECHANICAL APPLIANCES. 



169 



tory carnivora the upper and lower canines are arranged in such manner 
that the lower, the mandibular canines, lock in front of the upper ca- 
nines, so that any substance caught between them is firmly held, and 
it is necessary to tear the held substance to free it. Bonwill has pointed 
out another function for these teeth : it will be observed, when the jaws 
of an animal such as a lion or tiger are wide apart, that the tips of 
the canines upper and lower are in contact with one another, the lower 
in front and outside of the upper, thus the lower jaw is doubly held, 



Fig. 121. 



Fig. 122. 



Fig. 123. 



Fig. 124. 







Fig. 125. 



Fig. 126. 



in guides (Fig. 120), posteriorly by the temporo-maxillary articulation, 
anteriorly by the cuspids on both sides. In closing, the jaws can move 
in but one position — that which will bring the posterior carnivoral teeth 

exactly in the relation of shear- 
blades ; the canines, therefore, 
guide the other teeth of a den- 
ture into their proper occlusion. 
They markedly limit the lateral 
or rotary movement of the jaws ; 
so that in the human denture or in 

Fig. 127. 






animals where the rotary movements of mastication are pronounced, 
the canine becomes an insignificant tooth — it is reduced to an in- 
cisor. The tip of the canine cusp in man is occasionally so long in 
those dentures having a long overbite that its office as a guide to cor- 
rect occlusion is marked, and in such cases the prominent canine emi- 
nence overlying the length of the cuspid root is correspondingly large. 
In all typical human canines or cuspids the presence of the double cut- 
ting-blades at an angle with one another is the characteristic feature ; as 
both blades are functional, the tendencv of the root of this tooth is to 



170 THE SURGICAL ANATOMY OF THE TEETH 

be forced directly outward (Fig. 123), the direction of the resultant of 
the two forces received by the blades ; the stress is resisted by the un- 
usual root length and by its broadly rounded outer, labial wall, and 
again by the density of the overlying bone. 

The Bicuspids. — Mechanically the human premolars (the bicuspids) 
are double cuspids. Reverting to the function of the preceding classes 
of teeth, it will be seen that the incisors incise and cut off definitely 
sized masses of food, and on examining the nature of the occlusion of 
the upper cuspid and its antagonists it will be seen that the surfaces are 
so disposed as to flatten the mass previously incised, to press it between 
four surfaces. The double cuspid and the triple cuspids behind them 
— the upper molars — are so formed that the cutting-blades of the outer 
or buccal sections are sharper than those of the inner, the palatal, or 
lingual sections, and the cusps of each diminish in depth progressively 
to the last molar. While the cutting-edges of the molar-cusps are 
fitted for cutting, it is the squeezing surfaces which are of greatest 
functional importance. The stress upon the roots of these teeth is in 
three directions : outward, when the buccal cusps are in action ; inward, 
when the lingual cusps are in action, and there is a constant vertical 
stress (Fig. 1 24). The roots of these teeth are, therefore, of elliptical sec- 
tion to resist the inward and outward strains ; and cylindro-conical to 
resist the upward stress. These facts are of direct clinical importance in 
the restoration of lost crowns by fillings or artificial crowns, for if the 
occlusal surfaces are not so arranged that the root receives stress in all 
of these directions, and all stresses are not properly balanced, overstrain 
or disuse of some portion of the pericementum follows. This applies 
also to the incisor teeth, on which broad surfaces are sometimes added 
to artificial crowns without due regard to the distribution of stress in 
other parts of the denture. 

The first upper bicuspid, having deeper cutting-blades and a broader 
occlusal surface, requires a corresponding increase in the amount of root 
resistance afforded ; this is found in the usual bifurcation of the roots 
of these teeth. 

The Molars. — While the molars receive stress laterally upon their 
outer and inner cusp sections, the greatest stress to which they are 
exposed is nearly vertical. The stress outward is a very strong one, as 
affecting the roots of the teeth, mainly because of the increased breadth 
of the tooth. Pressure upon the buccal edges operates at a greater dis- 
tance from the axes of the teeth than in the bicuspids : hence the stress 
is greater. This fact is of clinical importance in that fillings and arti- 
ficial crowns are frequently made with too great a cusp length, thus 
increasing the stress upon the buccal roots. It will be seen that when 
the palatal cusps of the molars are in use the stress received by them is 



THE TEETH AS MECHANICAL APPLIANCES. 171 

usually in the axis of the palatal root, and the tendency toward dis- 
placement is minimized (Fig. 125). 

The upper third molar when in use presents a cusp-arrangement 
interesting when the nature of the occlusion is studied. The usually 
single palatal occludes with the broad depression between the cusps of 
the lower third molar (Fig. 126). The mechanical arrangement — a dull 
conical wedge in opposition to a broad basin - is one fitted for the 
crushing of hard but frangible bodies which rest in the basin of the 
lower molar, and are pressed upon by the wedge of the upper molar: 
A given amount of muscular power operates at this point with the 
greatest force, because, as will be seen, the lower jaw is a lever of the 
third class, the alveolar bone forming its long arm, so that the further 
back a tooth is in the dental series the greater will be the stress with 
a given amount of muscular power. 

The tripod disposition of the roots of the molar teeth is in corre- 
spondence with the stress directions upon their crowns ; the rocking 
action caused by the outward, inward, forward, and backward stresses is 
fully met by such a disposition of resistances. These movements, great- 
est in the first molars, find in this tooth a greater root-divergence. With 
a lessening of the lateral stresses in the hinder teeth there is a lessened 
root-divergence (Fig. 127), until with the third molar, where the stress 
is mainly vertical the roots are closely placed together, and the stress 
of direct pressure is diffused by a curving backward of the roots. 

In the foregoing, as in the succeeding, remarks it is fully recognized 
that during the period of the development of the teeth and jaws and 
during the eruption of the teeth influences are at work which may 
explain many of the anatomical peculiarities mentioned and cause 
variations from them, yet these features as described are in the main 
characteristic of the several teeth. 

THE LOWER DENTURE. 

Incisors. — The stress upon the lower incisors tends to force them 
inward, a displacement resisted not alone by the angles at which the 
elliptical section roots are set, but the pressure tends to close, to drive 
togethor the teeth of the lower incisive arch which afford mutual sup- 
port to one another (Fig. 128). The broader cutting-blade of the lateral 
incisor is accompanied by an increase in the size of the supporting root. 
The posterior cutting-blade of the lower cuspid is the longer, and it is 
upon this blade or upon its outer face that the greatest stress is received. 
Support against this stress is afforded, first, by the incisive arch, and, 
secondly, by the curvation of the deeply implanted root. 

Bicuspids. — The lower bicuspids are not truly bicuspid, the first 
being a cuspid with a partially formed second cusp. It has been de- 



172 



THE SURGICAL ANATOMY OF THE TEETH. 



monstrated by Bonwill that there is a well-defined anatomical reason why 
this tooth should not be formed as the upper bicuspid — i. <?., the inner cusp 
would be a constant interference with the cusps of the occluding teeth. 
It will be noted that the inward inclination which the buccal wall of 
this tooth has in common with the buccal walls of all the lower pos- 
terior teeth brings the axis of the cusp nearly in line with the axis of 



Fig. 128. 



Fig. 129. 



Ftg. 130. 






the root (Fig. 129), hence the tendency to lateral displacement is neu- 
tralized ; the pressure received upon the lingual surface of the bicuspid 
is antagonized by the angle at which the axis of the tooth is set to the 
perpendicular. The eight anterior lower teeth form an arch against 
which the anterior segment of the tongue exercises pressure. In a nor- 
mal denture the tendency to outward displacement which would arise 
in consequence of this pressure is prevented by the upper dental arch 
mechanically holding the lower in position. When the teeth of the 
upper arch are lost, this muscular pressure is frequently sufficient to 
cause outward displacement of the lower incisors. This tendency is 
more pronounced when from any cause the attachment of the lower 
incisors is lessened. 

The crown of the second lower bicuspid, having the inner cusp 
as an edge rather than a true cuspid section, has its greatest stress 
received upon the buccal cusp. The crown of this tooth is bent inward, 
so that its buccal cusp lies in a line which passes through the axis of 
the root. The stress is in two main directions, inward and outward ; 
although, as in all of the posterior teeth, there is also the antero-pos- 
terior stress. In all of the lower teeth in normal occlusion there is a 
tendency to mechanical displacement in a forward direction, which be- 
comes usually marked when the loss of a tooth deprives the tooth pos- 
terior to it of its anterior support. 

Molars. — In the dental segment represented by the second bicuspid 
and the three molars Bonwill has pointed out that the buccal cusps are 
rounded and dull, while the lingual cusps are the sharp segments, an 
arrangement the reverse of that found in the corresponding upper 



THE JAWS AND DENTURE AS A MECHANICAL APPARATUS. 173 

dental segment. The greater extent of pressure upon these teeth is 
received upon the buccal segments, and the tendency to displacement is 
therefore inward or lingually. 

The Jaws and Denture as a Mechanical Apparatus. 

Recognizing, as has been shown, that disarrangement of the mechani- 
cal disposition of any tooth is followed by an alteration of the local 
physiology, the principle needs elaboration from another aspect — that is, 
the teeth are to be viewed not only singly, but as integral parts of the 
entire dental system ; which is, first, the sum of the single teeth, 
together with the mechanism and physiology of the motor appa- 
ratus. These are to be studied : the jaws themselves and associated 
parts, and the details of their function. 

As emphasized by Harrison Allen, 1 the maxillary bones, particularly 
the superior maxillse, although in close relationship with the cranial 
bones enclosing the great nervous ganglia, yet belong to the visceral 
skeleton ; 2 they are but attachments to the'neural skeleton. 

The teeth are arranged and are contained in recesses of two portions 
of this visceral skeleton, one, a fixed or immovable mass of bone, which 
has a definite distribution of its masses fitted to afford great resistance 
and to dissipate force, to minimize the amount of shock transmitted to 
those portions of the neural skeleton, the basal cranial bones, which 

Fig. 131. 



Architectural scheme of the upper jaw : o, nasal column ; b, malar column ; c, infra-orbital arch : 
d, supra-orbital arch ; e, pterygoid column ; /, upper nasal half-arch ; g, lower nasal half-arch ; 
h, maxillary arch. 

enclose the brain-masses. The second, a movable mass, operating from 
centres which are in apposition with the brain-case proper, and in which 
another mechanical arrangement dissipates energy transmitted to the 
areas of contact between the visceral and neural skeleton. 

A. H. Thompson, 3 enlarging upon Allen, divides the disposition of 

1 "Studies of the Facial Region," Dental Cosmos, 1874. 

2 See also Hertwig's Embryology. 3 Dental Cosmos, 1893. 



174 



THE SURGICAL ANATOMY OF THE TEETH. 



the bone-masses of the superior maxilla (Fig. 131) into columns afford- 
ing resistance to the force received. A nasal column, its axis passing 
through the cuspid tooth, and ascending to the inner margin of the 
orbit, crossing the nasal bone at an angle to meet a corresponding 
extension from its fellow of the opposite side. A second column 
rising perpendicularly from the margins meets the orbital rim at its 
outer side ; the rim of the orbit furnishes two arches, a supra- and 
an infra-orbital arch. A third column or girder passes in a curved 
line nearly at right angles with the other columns. " The latter 
column serves to brace the bone against the lateral stress of mastica- 
tion ; the other columns against that of direct occlusion." " The loss 
of the cuspids deprives the face of its normal fulness due to the canine 
column, a fulness not replaceable by mechanical means." Minor braces 
may be outlined, all defending the maxilla against injury from the forces 
received by it. 

The greatest force of impact received by the molar teeth is by the 
superior maxillary articulations, dissipated through arches and projec- 
tions of the neural skeleton, so that concussion of the cranial contents is 
reduced to its lowest limits. 

Examining the detached inferior maxilla, it will be seen that it is 
also provided with strengthening columns (Fig. 132), which protect 
it from injury by the stress received upon it. The mental co- 
lumn, as shown, is a line of great resist- 
ance, but behind it the point of emergence 
of the mental vessels and nerves, the men- 
tal foramen, is a line of weakness, pro- 
tected, however, by the usually increased 
thickness of the cortical bone on this line. 
Despite this, however, a perpendicular line 
passing through the mental foramen repre- 
sents usually the line of least resistance. 

The lateral columns of the external and 
internal oblique lines are the columns of 
great resistance against both lateral and 
direct stresses. The condyloid column is an 
efficient brace at the rear edge. It is found with some degree of fre- 
quency that these columns are traversed by lines of lessened resistance. 
A constant line of lessened resistance crosses the coronoid and condyloid 
columns transversely and at an angle on a line above the attachment 
of the internal pterygoid muscle. 

As tersely stated by Thompson, the superior maxilla with its teeth 
represents the static element of mastication ; the inferior maxilla with 
its teeth and its attachments, the dynamic element. 




Architectural scheme of the lower 
jaw : a, mental column ; b, coro- 
noid column ; c, condyloid col- 
umn : d, body arch or curve ; c. 
arch of the symphysis ; /, molar 
arch. 



THE JAWS AND DENTURE AS A MECHANICAL APPARATUS. 175 

The lower jaw is a lever of the third class : the condyle is at the 
fulcrum ; the horizontal distance from the condyle to a line passing 
through the coronoid process and the angle of the bone, the short or 
power-arm ; from the condyle to the mental column is the length of the 
long or weight-arm. The power of the lever is represented by the 
action of the temporal, masseter, and of the pterygoid muscles, partic- 
ularly the internal, when right and left muscles act synchronously. The 
weight is the amount of pressure brought to bear upon substances be- 
tween the teeth. The weight upon the incisors, these teeth being at the 
extremity of the weight-arm, is less in amount than that upon teeth 
posterior to the incisors ; with a given force of muscular contraction, 
the greatest power is exercised at the third molars, in accordance with 
the mechanical law of 

W X L = P X L' or P X be = W X ea. (See Fig. 133.) 

Black l records the amount of force which can be exerted by the 
jaws. He found that the maximum force of those whose jaw-power 

Fig. 133. 




was tested, to be 175 pounds on incisors, and in the same individual 240 
pounds on the molars. The minimum force recorded for adults was 
30 pounds on incisors and 70 pounds on molars. While in many of 
the cases tested the ratio between the force exerted through the incisors 
approximated one-half that exerted through the molars, which corre- 
sponds quite closely with the mechanical positions occupied by incisors 
and molars on the mandibular lever, many other cases showed a ratio 
of 1 to 3, and some 1 to 1J. These discrepancies occur with sufficient 
frequency to show that the condition of the pericementum of teeth has 
more to do with the force exerted upon them than has mechanical posi- 
tion. With an average distance from condyle centre to the cutting- 
edges of the incisors of four inches, and a distance from condyle centre 
to the axis of muscular action of about 1^- inches, when a force of 100 

1 Dental Cosmos, June, 1895. 



176 THE SURGICAL ANATOMY OF THE TEETH 

pounds is brought to bear upon the incisors the muscles are exerting a 
contractile force of 266f pounds. 

4 X 100 = 11 x x = l-l- x = 400 x = 266J pounds. 

The amount of force necessary to crush food-stuffs by direct action 
ranges from 30 pounds for tender meats to 90 pounds for tough, fried 
meat ; hard crusts resist a pressure of 250 pounds ; hard candy 
requires in the neighborhood of 100 pounds. The stress exerted upon 
temporary molars, about 70 pounds, is quite sufficient to crush ordinary 
meats. In affections of the pericementum of a hypersemic nature the 
sensitivity of the pericemental nerves is much increased, so that less 
pressure can be exerted than in health. According to the investigator 
whose work is quoted, many persons involuntarily fail to exert sufficient 
masticatory power owing to the debility of the pericementum of one or 
more teeth. 

The Dental Mechanism. 

The dental apparatus operating upon an arm of a lever and against 
a fixed base has, normally, a definite arrangement of its members, 
making one of the most admirable anatomical structures conceivable. 
Dentistry is indebted to W. G. A. Bonwill, of Philadelphia, for the 
working out of the details of the dental mechanism. 1 

The teeth are arranged in two arches, an upper and a lower, the upper 
being the larger and overlapping the lower at its labial and buccal as- 
pects. In the lingual cavity the lower arch projects beyond the upper. 
These arches are usually parabolic, although at times semi-elliptical, 
and in some cases the dental series, upper and lower, form three sides 
of a trapezoid having rounded angles. As a rule, the distance from the 
centre of one condyle to the mesio-occlusal angles of the lower central 
incisors is about four inches, which is also the distance from the centre of 
the right condyle to that of the left, lines of junction through these 
points forming an equilateral triangle. 2 It follows, of course, that in 
a normal denture the equilateral triangle is also to be included in the 
lines joining the centres of the glenoid fossae and running to the junc- 
tion of the upper central incisors. 

The occlusal surfaces of the teeth are arranged in a definite manner. 
The first bicuspid tooth of the upper jaw is the anatomical basis from 

1 This description of the dental mechanism is largely derived from the written works 
and personal communications of Bonwill. 

2 In Bonwill' s written communication he attaches an occult significance to a series of 
measurements, based upon the equilateral triangle in the measurement of the sizes of the 
teeth and the determination of their positions. The facts cited are in the main correct, 
but are not, as Bonwill believes, a conclusive argument against the truth of organic 
evolution. His laws are as all anatomical laws subject to variation, although unusually 
constant. 



THE DENTAL MECHANISM. 



Ill 



which deductions may be drawn : first, the deeper the cusps of this tooth ; 
for the character and depth of the cusps of all the teeth may be deter- 
mined by an examination of those of the first bicuspid, the more the 
upper teeth overlap the lower, the overlapping being most marked in 
the incisors, and least with the third molars ; secondly, the teeth of a 
denture have not their cusp-edges on a plane ; a plane surface laid 
upon teeth is in contact with the edges of the central incisors, usually 
with the cuspids, bicuspids, and the anterior cusp of the first molars : the 
cusps of the second molar are at a distance from the plane, and those of 
the third molar at a greater distance — that is, the line of the molar cusps 
curves upward (Fig. 134). If the cusps of the teeth be very long, the 

Fig. 134. 




Front and side views of the teeth and jaws. 

cuspids may sink beneath the surface of a plane resting upon bicuspids 
and incisors. The longer the cusps the more pronounced is the upward 
curve. A plane laid upon the lower teeth touches the occlusal edges of 
the incisors, cuspids, and only the distal cusps of the third molar ; the 
second bicuspid, first and second molars, are below the plane, the first 
molar farthest below. The depth of this depressed curve is, as in the 
upper teeth, governed by the length of the cusps. In cases where the 
cusps are abraded the occlusal surfaces are reduced almost but not 
entirely to a plane. Thirdly, it will be observed that the buccal 
cusps of the teeth, from the second bicuspid backward, are at higher 
points than the palatal cusps, so that if a curved and plastic plane be 
pressed so that its surface is in contact with the cusps of all of the teeth 
of one side it will assume the form shown in Fig. 135. The longer the 
cusps of the teeth — i. e., the greater the overbite, and in consequence 
the greater the upward curve of the arch — the more the surface of the 
plane will be bent. 

12 



178 



THE SURGICAL ANATOMY OF THE TEETH. 



Placing the two dental arches in normal relation with one an- 
other, it is seen that each tooth (Fig. 134) is in occlusal contact 
with two teeth of the opposite jaw, with the exception of the lower 
central incisors and the upper third molars, which teeth have but one 
antagonist. The interspace between any two teeth of either jaw passes 
nearly through the vertical axis of a tooth in the opposite jaw. The 
arrangement is such that should a tooth be lost, its occluding teeth still 
have each an antagonist, except in the case of the four teeth which have 
but a single antagonist. Teeth having but a single antagonist are lost 
through a process of gradual extrusion after the loss of their antagonist. 

In the act of incising food the jaws are first separated and the lower 
jaw advanced until the cutting-edges of the upper and lower incisors 

Fig. 135. 




The horizon of the line of occlusion and plane of occlusion. 



are opposite one another. While the jaws are in this position with 
the incisors in occlusal contact they do not bear alone the stress of what- 
ever muscular force is applied, but it will be seen that the distal cusps 
of the third molars, the highest points of the lower dental arch, advance 
and meet the distal cusps of the upper second molars, higher points of 
the dental arch, so that when the incisors are in edge-to-edge occlusion, 
although all of the other teeth are separated to an extent governed by 
the overbite, the dental arch is supported posteriorly by contact of the 
last molars, thus preventing undue stress upon the incisors. As the 
incisors glide past one another the lower jaw recedes, and an increasing 
molar area comes in contact. 

The teeth of man, being of the omnivorous type, adapted both for 
incising and grinding food, the lateral movement of the jaws is of 
extreme interest. While the posterior teeth of man, notably in those 



THE DENTAL MECHANISM. 179 

individuals having long cusps to their teeth, have a distinctly carnivorous 
character, yet it is of secondary prominence as compared with the her- 
bivorous character of the molars. 

To do the actual work of the mechanical subdivision of food, of 
course the cusps and molar surfaces of the teeth must be in effective 
contact. After a mass of food has been excised by the incisors and 
pressed between the cuspids it is passed to the posterior teeth, and the 
lower jaw is swung toward that side, when it is seen that from cuspid 
to molar the rounded buccal cusps of the lower teeth rise until they 
are in contact with the sharp buccal cusps of the upper teeth. Upon 
the opposite side the teeth are in contact at two or more points, sup- 
porting the arches against overstrain, but are not in functional use ; only 
one side of the jaw is in functional use at one time, the food-masses 
being shifted from side to side until mastication is completed. 

The mechanism for the proper subdivision of the food, the func- 
tion of mastication, being as described, it is evident that aberrations of 
tooth-arrangement, the loss of a single tooth or of a column of teeth, will 
be followed by a corresponding interference with mastication. Aside from 
the aesthetics offended by the abnormal positions of teeth, there is a dis- 
tinct pathological interest involved in them, as- shown in the chapters 
on Malpositions of the Teeth and Diseases of the Pericementum. 



CHAPTER IX. 

DENTITION: ITS PROGRESS, VARIATIONS, AND ATTENDANT 

DISORDERS. 

The process of teething, the eruption of the teeth, technically called 
the process of dentition, may be defined as the vital operations through 
which the partially formed teeth are elevated from their beds in the 
maxillae until the gum is pierced and the crowns assume their ana- 
tomical positions in the dental arch. It includes a consideration 
of the completion of root-formation and the coincident development 
of the alveolar walls. It is evident, therefore, that a study of the 
process of dentition is a continuation to the study of dental embry- 
ology ; being, in fact, the later stages of a developmental process which 
began in the sixth week of embryonic life in an involution of the epi- 
thelium upon the summits of the jaws, and has its physiological termina- 
tion in the apical constriction of pulp-tissue due to the formation of the 
anatomical apex of the root. Physiological dentition is divided into two 
groups : first, the eruption of the temporary or deciduous teeth — first 
dentition ; secondly, the eruption of the permanent teeth — second 
dentition. 

Causes op Eruption. 

Explanations as to why teeth erupt are unsatisfactory and many of 
them conflicting ; none which has been advanced is sufficient to explain 
all of the observed phenomena. Nearly all of the hypothetical explana- 
tions advanced may be included in two classes — the dynamic and the 
vital. Those who subscribe to the dynamic vieAv hold that the process 
of dentition is due to the pressure of the forming root upon the tissues 
beneath it, causing reciprocal pressure on the overlying tissues ; resorp- 
tion of the latter tissues occurs and the tooth-crown emerges through 
the gum. The vital theory regards eruption as a physiological pro- 
cess which carries the developing teeth, practically uninfluenced by the 
pressure-element, into their positions in the dental arch. The prin- 
cipal objections stated to the dynamic theory 1 are that stunted teeth 
erupt ; that is, teeth having roots so short that downward pressure is 
insufficient to explain their emergence in the dental arch are found in 
the dental arch ; and, also, that the distance travelled by the crown of 

1 Tomes, Dental Anatomy, fourth ed. 
180 



PROCESS OF DENTITION. 



181 



a tooth in the process of eruption is greater than the length of the root. 
These objections are, however, more apparent than real ; and comparing 
the observed phenomena with the dynamic theory, it is probable that 
the pressure of the developing root, and the tissues about it, are at 
least very important elements in the process ; and yet it mast be borne 
in mind that the changes occurring in the entire mass of alveolar bone 
are as marked as is the alteration in the position of a tooth in its erup- 
tion. The alveolar changes do not cease until long after eruption. 

Process of Dentition. 

Dentition may be said to begin when the crown of the tooth 
approaches the covering of the bony crypt in which it is lodged and 
resorption of the edges begins. This occurs shortly after the time of 
beginning root-formation. The relations of the parts at this period are 
as follows : each tooth-follicle is lying in a crypt of bone, separated 
from the bony walls by thick layers of fibro -vascular tissue upon all 
sides. The bone of the floor of the crypts is the roof of the inferior 
dental canal in the lower jaw. In the upper jaw the floors of the crypts 
are not far beneath the level of the infra-orbital foramen, from which 
point they will be far distant in the mature jaw. The crypts are almost 
roofed by the bone overlying crowns, although a fissure exists in the 
roof of each crypt at its anterior portion. The teeth when in position 
will have their necks somewhat beyond the site of these fissures ; their 
roots, still unformed, will extend from this point to nearly the base of 
the existing crypt, and instead of lying loosely in their roughly spher- 
ical crypts, the future roots will be embraced by deposits of bone sepa- 
rated from the roots by an attenuated portion of the follicular wall. It 
will be seen, therefore, that not only must a larger deposit, in point of 



Fig. 136. 



22 months after birth 
18 months after birth _ 



12 months after birth 



6 months after birth 



40th week (birth) . 
30th week embryo . 

18th week embryo . 
17th week embryo . 




Calcification of the deciduous teeth. (Peirce.) 



length, of dentin be formed than in the crown, but bone is to be formed 
beneath and about the sides of this root sufficient to hold firmly the, 
at present, loosely placed tooth. 



182 



DENTITION. 



Whatever the cause, as soon as root- formation begins the crown of 
the tooth commences its journey toward the gum-surface. It will be 
observed that the resorption of the bony impediment to the advance is 
upon the anterior edge (Fig. 66). When sufficient of the bony impedi- 
ment has been removed, through the agency of osteoclasts, to permit the 
passage of the crown of the teeth, the gum-tissue is next resorbed, until 
the tip of the croAvn emerges and finally takes its anatomical position 
upon the summit of the jaw. The time at which this occurs differs 
with the classes of the teeth. As has been said, eruption is a phase of 
tooth-development beginning shortly after the completion of the crowns 
of the teeth, and it has been seen that the individual teeth differ as to 
the extent of their formation at a given time (Figs. 136). 'The teeth 

Fig. 137. 




Deciduous teeth. Left side. 



make their appearance in the dental arches when root-formation is 
more than half complete. 

Periods of Eruption. 

As a general rule, the eruption of the deciduous teeth may be said 
to begin about the seventh month after birth, and is completed some- 
where about the twenty-fifth month. This rule, however, varies within 
wide limits ; some children may be born with teeth erupted ; there are 
classical examples of this precocity — Caesar and Richard III. j 1 again, the 
initiation of the process may not occur until the twelfth month or even 
later. 

The incisor teeth are usually erupted in pairs, the molars and cus- 
pids making their appearance in fours, the first molars in one group, 
the cuspids in another, and the second molars in a third group. The 
several groups require different lengths of time to complete their erup- 

1 York. Marry, they say my uncle grew so fast that he could gnaw a crust at two 
hours old ; 'Twas full two years ere I could get a tooth. Grandam, this would have been 
a biting jest. Richard III, Act II, Sc. iv. 



SYMPTOMS OF DENTITION. 



183 



tion, the time occupied in the eruption of the first molars being longer 
than that required for the eruption of the other groups. Between the 
appearance of additional groups of the teeth an interval elapses, no 
doubt a physiological provision, for, as will be shown later, the process 
of dentition is usually accompanied by evidences of more or less local 
disturbance, frequently by disturbances throughout the intestinal tract, 
and even reflex disorders of the central nervous system occur. It is 
believed, therefore, that the period which elapses between the eruption 
of the dental groups permits the organism to recover from the effects 
of previous disturbance before the new source of irritation appears. 

Table. 1 



Group 1. Lower central incisors. 

Group 2. ! Upper central and lat- 
eral incisors. 

i 

Group 3. Lower lateral incisors. 
Group 4. First molars. 
Group 5. ' Cuspidati. 
Group 6. Second molars. 



Time of eruption, 

7 months. 
Time of eruption, 

9 months. 

Time of eruption, 

12 months. 
Time of eruption, 

14 months. 

Time of eruption, 
18 months. 

Time of eruption, 
26 months. 



Duration of eruption, 
1 to 10 days. 

Duration of eruption, 
4 to 6 weeks. 



Duration of eruption, 

1 to 2 months. 
Duration of eruption, 

2 to 3 months. 

Duration of eruption, 

3 to 5 months. 



Interval, 2 to 3 mos. 
Interval, 2 months. 

Interval, 4 to 5 mos. 
Interval, 3 to 5 mos. 



In the accompanying table it will be noted that the time of erup- 
tion of the lower lateral incisors is later than that of the eruption of the 
upper lateral incisors. The reverse course is frequently observed ; in- 
deed, it has usually been accepted as the rule of precedence in the 
United States. All tables as to periods of eruption give but the ap- 
proximate times ; while variations are extremely common, the ages 
given in this table are those at about which the several teeth may be 
expected to make their appearance. Stellwagen (the American editor 
of Coleman), in commenting upon this table, states that the periods of 
eruption in this country are from one-seventh or more earlier than the 
dates given. He suggests that the difference in food-habit may account 
for the differences in time. 

Pari passu with the development and eruption of the teeth are devel- 
opmental changes in all of the glandular appendages of the alimentary 
canal in such wise that alterations in their structure, and no doubt in 
their physiological chemistry, are accompanied by dental provision for 
the mechanical subdivision of foods of post-infantile character. 



Symptoms of Dentition. 

The process of dentition, like that of parturition, although un- 
questionably a physiological one, is even under normal conditions 

1 Coleman's Dental Surgery (Stellwagen). 



184 DENTITION. 

attended by phenomena which would usually be called pathological. 
The general characteristic of all physiological processes is that they are 
carried on without that form of consciousness of the individual termed 
pain, a course rarely noted in either parturition or dentition. Within 
physiological bounds, therefore, we expect evidences of local disturb- 
ance as an essential part of the process of dentition. These are of 
a character which would be expected from a survey of the existing 
conditions. The erupting teeth are exercising pressure upon the tissues 
which overlie them and a process of resorption of these tissues is in 
progress. The parts about the tip of the erupting teeth are in a state 
of irritation. Normally the reaction to this irritation should not ex- 
ceed a mild active hyperemia, and probably there is a causal rela- 
tionship between the hyperemia and the presence of the cells, caus- 
ing resorption of tissue. The vascular reaction is evident ' in the 
usual deepening of color over the site of the advancing tooth, and 
when the tip of the latter is almost visible, being overlaid by the epi- 
thelium alone, the gum beyond the tip is hypersemic. The temperature 
of the part is elevated. As in all hypersemic conditions, in its early 
stages relief is afforded from the irritation by pressure. It is common to 
find the infant instinctively seeking relief by pressing the fingers against 
the gum, and its mental irritation is appeased by having the finger of 
the attendant rubbed upon the gum over the advancing tooth. In 
the same manner biting upon hard substances, such as teething-rings, 
affords relief. Still more marked is the soothing effect of biting upon 
cold substances, such as ice which, in addition to mechanically less- 
ening the local blood-supply, causes contraction of the dilated vessels. 
The parts about the erupting tooth give every evidence of being in a 
hypersensitive condition, not alone as a direct consequence of the 
hyperemia, but also from direct pressure upon nerve-filaments. The 
evidences of nervous disturbance are both direct and indirect : the 
direct being those of local hyperesthesia ; the indirect are those in- 
dicating reflex disturbances, the most constant of which is usually a 
hypersecretion of saliva, the local disturbance reflexly stimulating the 
salivary glands to increased functional activity. Disturbances of the 
alimentary canal, while common, belong to pathological rather than to 
physiological dentition, as do also disturbances of the central nervous 
system. 

Prognosis and Treatment. 

Unless the process of dentition be accompanied by symptoms of 
greater severity than those above described, it will go through its 
course unaided, and calls for no interference. With the eruption of 
the molars and cuspids the irritation will be exaggerated, as these 



PATHOLOGICAL DENTITION. 185 

teeth are usually erupted in series of fours, and present through their 
forms mechanieal obstructions to eruption. While normally progress- 
ing dentition calls for no interference, it does emphatically demand 
that precautions be taken to prevent an abnormal course. The in- 
fant must be properly fed and nourished. If it do not appear to 
thrive upon the food it is receiving, the food should be changed, and 
if necessary again changed until it is found to subserve its purpose — 
sufficient nourishment. The question and problem of infant-feeding 
are fully discussed in works upon diseases of children, 1 and concern the 
general rather than the dental practitioner. 

It is of the utmost importance that the alimentary canal should be 
kept in a physiological and aseptic condition. Even in cases where den- 
tition appears to be pursuing a regular course the period is marked by 
various evidences of irritation and disordered function of the alimentary 
tract. Although there is not in all cases an evident causal association 
of teething with these disturbances, it is noted clinically that the symp- 
toms disappear if treatment directed to oral causes be pursued. As- 
suming, as is warranted by evidence, that the oral condition attendant 
upon dentition will permit the growth in the mouth of micro-organisms 
which do not flourish there normally, and that their passage into the 
stomach and to the intestines is followed by various fermentations — 
decompositions — the products of which act as local and in some cases 
general irritants, intoxicants, or poisons, it is evident that the removal 
of the morbid conditions of the mouth, preventing by this and other 
means the development of organisms in the mouth, will materially lessen 
the abdominal symptoms. It is found clinically that antiseptic treat- 
ment of the oral cavity is followed by a lessening of the evidences 
of intestinal fermentation, which, of course, receive appropriate treat- 
ment also. These subjects, however, belong to pathological dentition ; 
but presenting as minor symptoms during the course of apparently 
normal dentition, they demand and must receive attention. 

A normal course of dentition may frequently be assured by proper 
precautions, which, if not taken, will be followed by a train of disorders, 
painful and uncomfortable, if not dangerous. 

Pathological Dentition. 

When the common symptoms noted become exaggerated the progress 
of the dentition may be deemed pathological. 

SYMPTOMS. 

The symptoms attendant upon pathological dentition cover a wide 
range, beginning as evidences of pronounced local hyperemia, with all 

1 Starr, Infant-feeding ; J. Lewis Smith, Diseases of Children. 



186 



DENTITION. 



of its attendant symptoms and consequences ; the other extreme is 
attended by profound disturbance of the central nervous system, con- 
vulsions, coma, and death. That a fatal issue should follow or be 
consequent upon pathological dentition has been seriously questioned by 
most authors of works upon diseases of children, but cases have been 
observed wherein no other sufficient source of irritation was discover- 
able, and, furthermore, there are many cases on record where appro- 
priate treatment directed to the dental organs has been followed by the 
disappearance of serious disturbances of the central nervous system. 

According to the symptoms observable, which may furnish the only 
indication of the pathological conditions present, morbid dentition 
may be classed under two heads : first, cases in which all disease- 
conditions appear to be local ; secondly, those in which other and dis- 
tant organs give evidence of disorder. These may again be subdivided 
according to the severity of the local and general symptoms. 

Local Symptoms. — Instead of the normal localized hyperemia of 
the gum, with its hypersensitivity and reflex increase of secretion, 
evidences of active inflammation may be observed : the gum assumes 
a dusky hue ; if the apex of the tooth be about to penetrate the gum, 
the epithelium may be swollen and the area of vascular injection be 
larger. The tissues are swollen, the temperature is elevated, and the 
child gives evidence of painful local disturbance, notably by fret- 
ful crying, and by seizing the breast or bottle-nipple and quickly 
releasing it as soon as bitten upon, indicating pain upon pressure. 
The sleep is broken, and if the symptoms continue the child soon 
suffers from insufficient nourishment. The readiness with which the 
child will take cold substances, ice or ice water, is notable and self- 
explainable. Pressure and rubbing of the gum at a point distant from 
the focus of irritation afford relief. These symptoms usually subside 
with the appearance of the tooth through the gum, although in case of 
erupting cuspids local disturbances frequently persist until the entire 
crown is erupted. 

In the more marked cases of local disturbance evidences of bacterial 
infection of the mucous membrane of the mouth make their appearance, 
such as ulcerative stomatitis ; while, as a rule, the breaking down and 
ulceration of the tissue are confined to the parts overlying the erupting 
teeth, a general stomatitis or widely scattered patches of ulceration 
may make their appearance. The localized condition has been called 
odontitis i n fa ntu m . 

General Symptoms. — Intestinal Disturbances. — It is with cases 
of this type and with those of greater severity that disorders of the alimen- 
tary canal are commonly associated. These may express themselves in 
diarrhoea, with discharges of a " chopped spinach " character, in a serous 



PATHOLOGICAL DENTITION. 187 

diarrhoea, but in some cases obstinate constipation may be noted. It 
is the rule, even in the milder of these cases, to find the stomach reject 
food immediately or soon after feeding. In the diarrhceal cases excoria- 
tion of the anus is frequently found, indicating the irritating nature of 
the alvine discharges. In addition, the child suffers from the pains of 
colic — i. e., spasmodic contraction of the intestinal muscles and the gen- 
eration of gases. All of these symptoms clearly point to abnormal 
fermentative changes occurring in the contents of the intestinal canal, 
and as clearly indicate the therapeutic measures likely to be useful. 

Skin Disorders. — It is so common as to be almost termed the rule 
to find at the time of these intestinal symptoms that there are eruptions 
observable on the skin. The mildest form of these is a herpetic erup- 
tion about the mouth ; in other cases papular and vesicular eruptions 
are observed upon the skin of the body and limbs. 

Pulmonary Symptoms. — The close association of the fifth and 
tenth cranial nerves is frequently cited in dentistry, notably in connec- 
tion with shock from operations ; another expression of it may be noted 
in the laryngeal cough which sometimes attends the eruption of groups 
of teeth, and which disappears upon their eruption. 

Nervous Disorders. — Disorders referable to the central nervous 
system are the most alarming, and are those indicating the higher 
grades of severity of irritation. The milder forms of these disturb- 
ances are faint muscular twitchings. The child wakes out of sound 
slumber with an irritable cry, and is soothed with the utmost difficulty ; 
it dozes, only to be awakened again. In these cases there are usually 
other morbid symptoms, such as the disturbances of the alimentary canal 
described above and the evidences of oral affection. These symptoms 
may occur without any such evident connection with the teething-process 
that a probable causative association with dentition is not made out. 
In fact, in the absence of evident local irritation the association of 
teething with the general disturbances is frequently denied, but in 
refutation of such a position it is noted that treatment based upon 
morbid dentition as the cause of the nervous disturbance is commonly 
followed by a disappearance of the latter. There is much doubt as to 
the precise nature of the dental irritation in such cases, as there is no 
morbid condition of the parts overlying the erupting teeth which would 
serve to explain the irritation. It is assumed with good reason, there- 
fore, that the irritation is of the pulp itself; that the tissue of the pulp 
is being subjected to pressure through the processes of tooth-building 
and tissue-resorption not proceeding harmoniously. The source of irri- 
tation has been by some authors ascribed to an inflammation of the 
follicle. Certainly such an inflammation might occur in the tissues 
immediately surrounding the tooth ; but in that event we should expect 



188 DENTITION. 

to find associated disorder of the overlying tissues, which is frequently 
not the case. 

A distressing symptom not easy to elicit on account of the age of 
the patient is headache. The child is sleepless, and cries without 
apparent cause ; it becomes quiet, partially from exhaustion, and after a 
period again commences sobbing. The indication of central disturb- 
ance may at times be noted in the contracted pupils of the eye and 
in throbbing arteries. The usual treatment, the administration of 
chloral hydrate and potassium bromid, with cold applications to the 
head, furnishes relief, which is frequently not complete without atten- 
tion to the dental organs. 

In the more severe and dangerous cases the evidences of disorder 
of the central nervous system become unmistakable. These appear 
as clonic convulsions or symptomatic eclampsia. While it is probable 
in many cases that reflex irritation from the process of dentition in 
itself is but a secondary cause of convulsions, yet evidence is sufficient 
to warrant its being regarded as a determining factor. In very many 
cases teething-convulsions appear to indicate a neurotic family taint, 
and eclampsia may attend many disorders in children of this type, 
notably the mechanical and chemical irritation induced by the presence 
of large masses of indigestible food in the intestines. 

So-called teething-convulsions occur usually at a time when several 
— an abnormal number — teeth are in process of simultaneous eruption. 
The onset of the convulsions is rarely, although apparently often, 
sudden. If the child be closely observed, it is noted that a period of 
cerebral disturbance — fretful crying, eA T idences of headache, sleepless- 
ness, etc. — is followed by a period of dulness and somnolence, or the 
child may lie with eyes half-open. Twitching of one or more groups 
of muscles may be observed ; the orbicularis oris and other muscles of 
the lips, and the muscles of the eye, notably the superior and internal 
recti, may contract spasmodically. A common muscular spasm usher- 
ing in convulsions is that of the adductor muscles of the thumbs ; the 
thumbs are drawn toward the palms of the hands. The adductor mus- 
cles of the feet contracting, the feet are drawn inward. This period 
may be ushered in by a sharp cry, the eyes roll upward with the lids 
half-open, and consciousness is lost. The symptoms may disappear, the 
child awakening dazed and fretful ; or it may sink into sleep. Unless 
the source of irritation be removed, or active therapeutic measures be in- 
stituted, the eclampsia may return and in severe cases be the precursor of 
death. 

TREATMENT OF PATHOLOGICAL DENTITION. 

There is no means for assuring a normal and smooth progress of 
dentition comparable in value with hygienic precautions. If intelli- 



PATHOLOGICAL DENTITION. 189 

gent care be taken of the clothing and diet of the child, together with 
measures to insure normal digestion, and due regard be paid to ventila- 
tion, in the vast majority of cases the period of dentition will be passed 
through with but trivial oral disturbance. In all cases of pathological 
dentition, therefore, a careful superintendence of these matters must form 
an essential feature of the treatment of the case. 

Treatment of Local Disorders. — Since conditions of hyperemia 
invite the development of micro-organisms, it is evident that steriliza- 
tion of the mouth must play an important part in the treatment of the 
irritation incident to teething. The importance of this measure is fur- 
ther emphasized by the researches of Miller, 1 who found that numer- 
ous forms of organisms associated with intestinal fermentations are pres- 
ent in the mouth, and develop when conditions favorable to their growth 
appear ; passing into the alimentary canal, those not destroyed by the 
acid gastric juice pass into the intestines and give rise to fermentations 
of the intestinal contents. 

The feeding-nipple, which should be of the simplest type, should be 
well washed in hot water after each use, then washed in a dilute anti- 
septic solution, and be kept submerged in it until needed. Each feed- 
ing-bottle should be sterilized in boiling water after using. The practice 
of the nurse rubbing irritated gums with the finger should be discoun- 
tenanced, as should also the use of teething-rings which are permitted to 
lie about and take up infective material. If hard-rubber, ivory, or 
metallic rings be used, they should be carefully sterilized by boiling. 

To reduce local hyperemia of the gum above an erupting tooth a 
common domestic measure is valuable, viz., a small block of ice is 
placed in a clean napkin, and confined in place by a knot ; the infant 
places it in its mouth at pleasure if old enough, or the nurse permits 
the child to bite upon it. The mechanical effect of biting upon a hard 
substance has added to it a degree of cold which lessens the local 
vascular engorgement. 

It should be noted that during the period of dentition children who 
are vaccinated against smallpox have the suffering incidental to teething 
much increased. 

More marked degrees of vascular engorgement, hence irritation and 
suffering, usually demand the relief by local bloodletting and lessening 
mechanical resistance following the operation of gum-lancing (see later). 

Should general stomatitis, with or without stomatitis ulcerosa, make 
its appearance, the mouth is to be promptly and freely sprayed with a 
3 per cent, solution of pyrozone, followed by a spray of potassic chlor- 
ate, gr. xx-^j, which usually affords prompt relief. Should the spots of 
ulceration not disappear promptly, the mouth and tissues about the 

1 Micro-organisms of the Human Mouth. 



190 DENTITION. 

ulcer are to be guarded by soft linen napkins ; each ulcer is dried and 
touched with carbolic acid, full strength. The spraying is to be re- 
peated at intervals of three hours during the waking period. This 
method of treatment is productive of decidedly better results than fol- 
low the use of the common formula of honey and borax. 

When evidences of active inflammation exist in the gum overlying an 
erupting tooth the indication is free gum-lancing with a blade of such 
razor-like sharpness that no pressure is exercised in the operation. 
Conjoined with this measure, to which is added spraying with pyrozone, 
steps should be immediately taken to empty the intestinal canal of its 
contents, as not infrequently constipation is an attendant condition. 
The constipation incident to some cases of stomatitis or gum inflamma- 
tion (gingivitis) may be induced or aggravated by the administration 
of soothing-syrups, which usually contain opium in some form. The 
same result is produced by the domestic use of soothing-syrups and 
paregoric (tr. opii camphorata) to relieve diarrhoea ; by lessening the 
sensitivity of the bowel and decreasing its peristaltic movements irritat- 
ing substances are retained in the bowel, a menace to the child's health. 
It is not intimated that opium in minute doses (and a one-drop dose of 
tr. opii deodorata is a very large one for an infant of eight or ten 
months) is not a valuable drug under some conditions, but its use should 
follow that of laxatives and intestinal antiseptics, not precede them. 

Treatment of Skin Eruptions. — The eruptions which appear upon 
the skin during dentition may be a source of annoyance to the child by 
causing itching. As a rule, measures directed toward a regulation 
of the intestinal functions cause a disappearance of the skin affections. 
If the eruption be widespread and cause much itching, a wash of phenol 
sodique, diluted to one-third with water, usually affords relief. If the 
surfaces be then dried and talc powder dusted over them, the condition 
is much alleviated. About the mouth and over excoriated surfaces an 
ointment of zinc oxid is useful. 

Treatment of Intestinal Symptoms. — These, in the vast majority 
of cases, call for two measures — evacuation and the use of antiseptics, the 
character of both evacuant and antiseptic to be determined by the nature 
of the case. It has been held that diarrhoea during dentition is due 
to a heightened irritability of the bowel, a reflex irritation, and seda- 
tives have been administered to lessen such hypersensitivity. That 
such a heightened sensitivity may be present and that abnormal progress 
of dentition may produce an irritable condition throughout the intestinal 
tract, are quite probable, but experience has shown, and modern patho- 
logical theories indicate forcibly, that the bowel-condition is caused by 
the action of irritating products of fermentation upon the walls of the 
intestine. As emphasizing the importance of prompt and effective 



PATHOLOGICAL DENTITION. 191 

therapeusis in this connection, it must be remembered that not only are 
the normal intestinal functions interfered with as a consequence of 
these fermentations, but a train of disturbances follows. First, normal 
digestion, both gastric and intestinal, is incomplete ; instead of forming 
nutrient solutions, the food undergoes abnormal fermentations, the 
products of which act as local poisons disordering the function of the 
bowel. Although absorption is lessened, it does not cease, and poisonous 
substances are taken into the portal circulation. There is no doubt that 
many of these poisons are chemically destroyed in the liver, but some 
of them may find their way into the general circulation and cause 
symptoms of toxaemia. In any event, the formation and absorption of 
assimilable pabulum are greatly lessened, and debility — i. <?., lessened 
vital resistance — is induced. The products of abnormal fermentations 
act as local irritants, causing irritation of localized or widespread areas 
of the intestine. Concentrated at some one portion of the length of the 
canal, they may cause spasmodic contraction of its muscular wall, the 
painful condition of colic. Other fermentations, or the same perhaps 
acting over large surfaces, induce irritative diarrhoea. So long as these 
conditions are permitted to exist all bodily functions suffer, and if denti- 
tion be in progress its course is interfered with. The probable causative 
connection between mouth and intestinal fermentations has been dis- 
cussed. 

Recognizing the cause of the condition in the presence of irritating 
substances in the intestine, the rational indication is to free the bowel 
from them. There is perhaps no laxative comparable with castor oil 
for this purpose. Children take castor oil better than adults. After 
the action of the oil, additional fermentation is checked by the use 
of anti ferments — antiseptics. Preparations of thymol, eucalyptus, ben- 
zoic and boric acids, such as listerine, are extremely useful in this con- 
nection ; ten drops in water may be administered every three hours. 
Both powders and solutions given to children may be sweetened by the 
addition of a minute quantity of saccharin, which has the additional 
advantage of being an intestinal antiseptic. The subsequent adminis- 
tration of magnesium hydrate is useful ; it has the advantage of allaying 
irritation by coating the mucous membrane ; and if acids be present, 
they combine with the magnesium, forming faintly laxative salts. To 
lessen great irritability and procure quiet a few drops of paregoric may 
be added to the magnesium fluid. Compound chalk powder — mist, 
pulv. cretse co. — is also used for this purpose. 

Treatment of Nervous Conditions. — Should the premonitory 
symptoms of disturbance of the nervous system make their appear- 
ance, attention should at once be directed to a search for the cause. If 
constipation exists, the bowels should be freely opened ; magnesium 



192 



DENTITION. 



citrate in effervescing solution is well taken. Clothing is loosened, cold 
applied to the head, and an examination of the gums made. If a 
tooth, or, as is more frequently the case, several teeth are in process of 
eruption at one time, their crowns partially or completely imprisoned by 
overlying gum, lancing should be done at once. More severe symp- 
toms call for more active treatment, the general therapeutic principle 
involved being the lessening of the cerebral blood-supply. This is 
most quickly accomplished by placing the child almost waist-deep in 
water as hot as can be borne and pouring cool water over the head, 
when, as a rule, the symptoms promptly subside. After immersion, a 
rectal injection of glycerin (one drachm) will usually cause a free stool. 
To insure a period of cerebral quiet it is advisable in the more severe 
cases to administer a cerebral sedative, a bromid preferably, which, if 
combined with chloral hydrate, which children bear well, will induce 

sleep : 

1^. Chloral, hydrat., 

Sodii brom., 

Starch paste, 

S. To be administered per rectum. 



gr. ij ; 
gr. v ; 
gij. — M. (Atkinson.) 



After sleep, if appearances indicating dental irritation be observed, 
gum-lancing is practised. 

It has been repeatedly noted that where evidence of marked cerebro- 
spinal irritation is present, for which no probable source can be 
assigned and an examination of the gums shows no apparent local 
disturbance, yet if it be at a period when one or more teeth are in 
process of eruption, but are still covered or bound down by gum-tissue, 
if gum-lancing be practised, relief is immediate and may even avert 
a threatened attack of eclampsia. It is presumed that these are 
cases of pulp-irritation in which a failure to sufficiently remove tissue 
in advance of the tooth-crown has caused pressure upon the pulp from 
below. 

Gum-lancing. — The operation of gum-lancing consists in making 
incisions through the gum-tissue overlying developing teeth in such 
manner as to remove mechanical obstruction to their advancement. 
The direction and character of the incisions are governed by the form 
of the advancing tooth (Fig. 138). 

The gum over the incisors and cuspids is divided on a line parallel 
with the cutting-edges of the teeth ; the cut over the upper incisors 
should be a little outside of the teeth-edges; that over the lower 
incisors slightly inside, so as to induce normal positions, the upper 
teeth outside of the lower. 

When the point of the cuspid has penetrated the gum-tissue the 



PATHOLOGICAL DENTITION. 193 

crown is still confined, owing to the conical form of the tooth, so 
that to effectually free it radial cuts may be necessary (0, Fig. 138). 
The gum over the molars, with the exception of the upper first, is 
divided in X-form, the cuts extending from cusp to cusp. The upper 

Fig. 138. 




Lines of incision in lancing: A, A, over the molars; B, B, over the cuspids and incisors before 
eruption ; C, C, over the molars and cuspids after partial eruption. 

first molar having but faintly marked cusps, and only an outer and 
inner cutting-edge to the tooth, is best freed by a crucial incision. 

The instrument to be used for dividing the gum is a pointed bis- 
toury of extreme sharpness ; its edge is to be wrapped in linen or cord 
until only a half inch from the point is exposed. This precaution is 
taken to avoid accidental wounding of the mouth. The child is to be 
placed and held in such position that the light shall fall upon the jaw 
to be operated upon, and so that no movements shall be permitted. It 
is advisable — almost necessary — to have an assistant hold the child in 
the proper position so that it cannot move head, body, or limbs. A 
position favorable for operating is to have the child lie upon its back 
between the knees of an assistant, the left hand of the assistant holding 
the hands of the infant, the right hand being used to steady the head. 
In another position the child sits upon one thigh of the assistant, the 
back of the head resting upon the chest, and the hand of that side 
(usually the right) pressed upon the child's forehead to hold the head 
firmly. The other hand and forearm hold the child's arms and hands 
firmly. 

The operator encloses the gam about the part to be cut with the 
thumb and forefinger of the left hand, so that the bistoury cannot slip 
and cut lip, cheek, or tongue. Incision over the erupting tooth 
should be made until the knife-blade is felt to touch the enamel- 
surface. The operation of scarifying the gums, making merely a few 
scratches to relieve engorged vessels, is but temporizing with the condi- 
tion ; the cut should be of sufficient extent to entirely remove tension 
from above the tooth. The little finger of the right hand may rest upon 
the chin of the child as an additional guard. 

13 



194 DENTITION. 

In case the crown of an erupting molar is confined by a block of 
tense gum attached upon two or more sides, the entire block is to be 
removed ; the block is drawn tense by means of traction with a tenacu- 
lum piercing the flap, and three sides freed by means of the bistoury 
point ; the final cut may be made with scissors of extreme sharpness. 

While it is true that in many cases children struggle under this 
operation, and give evidence that it -is a painful procedure, gum-lancing 
is frequently followed by immediate tranquillity upon the part of the 
child ; fretfulness disappears and nursing is resumed immediately after 
the operation, which occupies but a few seconds of time. 

More or less bleeding follows upon the operation, which, as a rule, 
ceases spontaneously. A sjiort period of bleeding is desirable, so that 
vascular engorgement may be reduced. Suckling by the infant usually 
serves to check the bleeding ; the tissues about the cut surfaces are com- 
pressed by tongue and lips during suckling, and bleeding ceases. In 
the event of the bleeding continuing the mouth should be carefully ex- 
amined, and a piece of ice in a napkin may be given the child to suck. 
Obstinate bleeding may require the use of styptics, but these should be 
of a character to cause only coagulation of the blood, not the destruction 
of tissue. A little powdered tannin laid upon the cut acts promptly, as 
does also a small amount of powdered alum. 

CONSTITUTIONAL STATES MODIFYING DENTITION. 

Children who are the victims of hereditary syphilis usually cut their 
teeth very early, the alveolar process being in many cases insufficient. 
Cases are recorded where children have been born with crowns of teeth 
visible upon the gum, there being no evidence of root-formation, the 
crowns being loosely held to the gum by fibrous tissue. It is necessary to 
remove these loose crowns to permit the infant to suckle. Children 
affected with rachitis have the process of eruption much delayed. It is 
seen, therefore, that the presence of loose crowns of teeth is a condition 
pointing to, though by no means diagnostic of, hereditary syphilis. Also, 
that long-delayed eruption of teeth should prompt a search for further 
indications of rachitis. Particularly in children in whom a history of 
hereditary syphilis is obtainable the process of dentition may be accom- 
panied by rapid and frequently widespread breaking down of the soft 
tissues over and about erupting teeth. Local measures of treatment 
seem to be of but little avail, except that antiseptic treatment un- 
doubtedly prevents complications from extraneous infection. 

In children classified indefinitely as strumous, which may mean the 
children of syphilitic or tuberculous parents, or those with no such 
history whose surroundings are of the most unhygienic kind, the process 
of dentition may not only have an untoward course, but phagedenic 



SECOND DENTITION. 195 

ulcerations may occur. It is usually in the degree of a child's debility, 
either inherited or acquired through improper care, that dentition 
assumes morbid features. The treatment of such cases must be di- 
rected to raising the health standard. As local therapeusis, no meas- 
ures seem more effective than the sprays of hydrogen dioxid first ; 
next, potassium chlorate, and, if conditions indicate it, sprays of 
dilute listerine, which is stimulant, antiseptic, and slightly astringent. 
Infantile Scurvy. — Cases are recorded l in which the improper 
feeding of children has been followed by evidences of scorbutus. The 
gums become tumid, and hemorrhagic extravasations occur in their sub- 
stance ; the periosteum is stripped from the margins of the alveolar 
walls, the soft tissues hanging in discolored pendulous masses about 
and beyond the teeth if any be erupted. Local treatment proving 
ineffective, the scorbutic nature of at least one of these cases was made 
clear by the disappearance of the oral disorder when the patient was 
placed upon an antiscorbutic diet. 

Second Dentition. 

The period of second dentition begins without disturbance of the 
temporary denture, by the eruption of the first permanent molars, pos- 
terior to the second temporary molars. At the period when this occurs, 
from five to seven years, all of the permanent teeth are in process of 
formation, even the third permanent molars, although none other of 
the permanent teeth except the first molars will normally appear in the 
dental arch for a year, or in some cases two years. The order in which 
the permanent teeth make their appearance varies, but the following 
table shows the approximate dates at which they may be expected to 
appear in the dental arch : 



First Molars, 


5* 


- 7 


years. 


Central Incisors, 


7 


- 8 


a 


Lateral Incisors, 


8 


-' 9 


a 


First Bicuspids, 


10 


-11 


u 


Second Bicuspids, 


11 


-12 


a 


Cuspids, 


12 


-14 


u 


Second Molars, 


12 


-15 


a 


Third Molars, 


16 


-20 


a 



and indefinitely beyond. 

With the exception of the permanent molars, all of the teeth 
have deciduous predecessors, the bicuspids being the successors of 
the temporary molars. 

At the time of eruption of the first permanent molars calcification 
1 E. C. Kirk, Proc. Odontological Society, New York, Dental Cosmos, 1895. 






196 



DENTITION. 



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has been for some time complete in the roots and alveolar process about 
the roots of the temporary teeth, and the roots of the deciduous in- 
cisors are already beginning to be 
absorbed, pari passu with the de- 
velopment of the corresponding 
permanent teeth. The permanent 
teeth are all at different periods of 
formation, differing in extent ac- 
cording to groups of fours : (1) cen- 
tral incisors, (2) lateral incisors, 
(3) first and (4) second bicuspids, 
(5) cuspids, (6) second molars, (7) 
third molars — group (1) being the 
first molars (Fig. 139). The figure 
exhibits the stage of tooth-forma- 
tion — l. e., the extent of calcifi- 
cation at successive periods. As 
calcification proceeds in the per- 
manent teeth having deciduous pre- 
decessors the latter suffer, first, 
loss of apical alveolar walls, and 
next gradual loss of root-substance, 
in exact correspondence with the 
growth of the permanent teeth. 
The lines in the illustration (Fig. 
140) show the extent of root-loss 
S of each tooth at successive periods. 
To comprehend the nature of 
the processes involved it is essential 
to obtain an accurate view of the 
anatomical conditions existing prior 
to and during the loss of the de- 
ciduous teeth and the appearance 
of those of the permanent denture. 
The teeth, both temporary and the 
partially formed crowns of the per- 
manent teeth, lie in that portion of 
the bone called the alveolar ; that 
is, the portion of the lower jaw 
above the inferior dental canal, and 
in the upper jaw below the infra-orbital foramen. The cuspid crowns in 
both jaws are more deeply seated than are any of the other teeth, 
and in the lower jaw are deeper than the mental foramen. Before 



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SECOND DENTITION. 



197 



resorption of the roots of the deciduous teeth begins the temporary 
teeth occupy a segment of alveolar bone of nearly as great a radius as 
that required for the permanent teeth, but the depth of which, from 
infra-orbital or mental foramen to the alveolar margins, is decidedly 
less than that of the adult jaw. In the base of this segment, separated 
from the bodies of the bones by bony lamina and from the pericemen- 

Fig. 140. 





I „ JLi i f i 

I 1Z 1MF^& 1 v ! Iff ii 





lo jgffflssggs 



Decalcification of the deciduous teeth. The numbers indicate years. (Peirce.) 

turn of the temporary teeth by a layer of bone, lie the developing 
permanent teeth, with the exception of the molars, which lie in the 
posterior portion of the alveolar bone, which at the period under con- 
sideration (about five years) is of slight extent compared with its adult 
size, both as regards depth and length. Its length, from the distal wall 
of the temporary second molar to the base of the coronoid process, is 
but little more than sufficient to easily accommodate the crown of the 
permanent first molar ; its depth between gum-surface and the roof of 
the inferior dental canal is but little more than sufficient to accommo- 
date the height of the crown. 

The buccal cusps of the crowns of the developing bicuspids lie in 
the triangular pyramidal depressions between the roots of the temporary 
molars, separated from the roots, as are all of the other crowns from the 
roots of their deciduous predecessors, by laminae of bone and perice- 
mentum. The crowns of cuspids and incisors lie inward lingually of 
the roots of the deciduous teeth. 



ERUPTION OF PERMANENT FIRST MOLAR. 

This tooth, vulgarly called, from the time of its eruption, the sixth- 
year molar, has a process of eruption similar to that of the deciduous 
teeth. Being the largest tooth of the dental series, the passage of its 
large crown requires the resorption of an extensive amount of gum 
and alveolar tissue ; this process is usually accomplished in the course 
of a few months. It differs in no respect from the physiological erup- 
tion of the temporary tooth. It is to be recalled that in the develop- 
ment of the jaws two divisions of the bone are recognized, the alveolar 



198 



DENTITION. 



portion and body portion ; normally their development proceeds together 
and harmoniously. With the growth of the alveolar process which 
forms about the roots of the permanent first molars the distances from 
the alveolar border to the levels of infra-orbital and mental foramina 
increase—/. e. 9 the alveolar bone is growing in height throughout its 
length. This growth normally causes a separation of the anterior teeth, 
which is to be regarded as the precursor to resorption of the roots of 
these teeth. 

RESORPTION. 

In advance of the crown of the tooth in process of eruption a num- 
ber of large multinucleated cells make their appearance, whose office it 
is to effect. the removal of tissue interfering with eruption. The origin 
of these cells is not known ; by some they are believed to be transformed 
osteoblasts, by others, leucocytes. The latter is the more probable expla- 
nation ; that is, these cells are phagocytes, named from their partic- 
ular function osteoclasts, or bone-destroyers ; those attacking and re- 
moving the roots of teeth are called odontoclasts. In the light of present 
physiological theories it is believed that these cells have a secretion cap- 
Fig. 141. able of digesting bony tissue and dentin ; 

that is, they remove molecularly the tissues 
interfering with eruption. It is possible that 
they secrete a ferment or solvent which effects 
the solution of bone and dentin, the solution 
being removed by the lymphatic system. 
As the result of the presence and life 
of these cells, first, disappearance of the 
bony lamina between the crowns of the 
permanent and the roots of the deciduous 
teeth occurs ; next, the roots of the latter 
are attacked when the permanent crown 
impinges upon the deciduous root. It is 
possible that this element of pressure, of ad- 
vance of the permanent crown, may be the 
cause of the presence of these multinu- 
cleated cells (see Chapter I., Reproduction 
of Cells). These cells lie between crown and 
root, and as the latter is removed the former 
advances. It will be observed from the re- 
lationship of parts that resorption does not 
begin at the very apex of the root. Those portions of the alveolar 
process which immediately surround the roots of the temporary teeth 
also undergo resorption, a new process being built about the roots of 
the permanent teeth (Fig. 141). 




Showing the relations of an erup- 
ting permanent tooth to its decid- 
uous predecessor : A, A, A, odonto- 
clasts. 



SECOND DENTITION. 199 

The process of eruption of the permanent second molars is the 
same as that of the first molars. The development of the jaws 
increasing the distance between the distal wall of the first molar and 
the base of the coronoid process, proceeds until there is space enough 
between the second molar and the coronoid process to admit the crown 
of the third molar, which erupts late, by a process similar to that of the 
other permanent molars. Not until this eruption is complete do the 
maxillse acquire their full adult forms. 

DISORDERS OF THE SECOND DENTITION. 

Provided that nothing occurs during the period of second dentition 
to interfere with the normal resorption of the roots of the temporary 
teeth, the process of dentition as regards the twenty-eight anterior teeth 
proceeds in an orderly manner. Given such interference, abnormalities 
of the second dentition make their appearance ; many of these will be 
discussed in the succeeding chapter, under the head of malpositions. 
It will be recalled that the teeth are an evolution of the dermoid sys- 
tem, which fact possesses pathological significance in certain acute and 
specific skin diseases. It is noted in some cases of the eruptive fevers 
of children, particularly when the child is much debilitated, that after 
the cessation of the acute disease a necrotic affection of the jaw occurs, 
involving the alveolar bone and its contents. As many of these cases 
occur between the ages of three and seven years, the temporary teeth 
are still in situ ; these with the partially developed permanent teeth and 
the enclosing bone may be exfoliated. The necrotic process may involve 
but one tooth, or may include all of the temporary teeth, their successors 
and a large mass of bone. 1 The disease with which this necrosis is most 
frequently associated is scarlet fever ; 2 it is also found as a sequel of 
measles and smallpox. It will be observed that all of these diseases 
are forms of specific dermatitis, and the teeth as part of the dermoid 
system are affected (see Chapter XI.). " The cases prior to exfoliation 
of the bone exhibit a stripping of the periosteum, apparently beginning 
about the necks of the teeth. A discharge of pus having a fetid odor 
is present, and the soft tissues may be raised from the bone for a vari- 
able extent ; " that is, there is evidence of purulent periostitis. In the 
course of some weeks, six or eight, the necrotic bone and its contents 
exfoliate. Salter observes that the sequestra forming after severe scar- 
let fever are much more extensive than those which form as a sequel of 
measles. 

Treatment. — In the absence of any guide as to the amount of bone 
which has died, the operator is compelled, as in all cases of necrosis, to 
adopt palliative measures, the most important one being the free and 

1 Salter, Dental Pathology. 2 Ibid. 



200 DENTITION. 

frequent use of antiseptic washes and sprays — hydrogen dioxid. The 
prescription of Garretson for such cases should be applied to hasten 
exfoliation and to stimulate still vital parts — i. e., enough tincture of 
capsicum and myrrh (tr. capsici et myrrhse) is to be added to a glass 
of water to cloud the water ; this is then to be used freely as a stimu- 
lant and astringent mouth-wash. As soon as the sequestrum is loose 
it should be removed ; the parts heal by granulation, provided due 
attention be paid to the general physical welfare of the child. 

Non-resorption of Temporary Roots. — The failure of resorption 
of the roots of temporary teeth will necessarily interfere with the erup- 
tion of the permanent teeth. Perhaps the most common cause of failure 
of root-resorption of the temporary teeth is to be found in septic con- 
ditions of their roots. Whether the pulp of a tooth performs any 
active office in the process of root-resorption is not known ; the 
evidence that it does is but imperfect and indirect, so that for the 
reasons of failure of resorption search must be made outside of 
the pulp-chamber. The pulp of a temporary tooth dead as the re- 
sult of invasion of caries undergoes decomposition ; infection of the 
pericementum occurs, and septic pericementitis results. An abnormal 
condition is established, and resorption does not occur ; the conditions 
are not favorable for the presence and activity of odontoclasts ; should 
they be present, their vital activities are poisoned by the products of 
the micro-organisms present — instead of functionating they die. An 
irregular resorption does, however, occur over some portions of the 
roots. If the purulent condition be removed and the parts be made asep- 
tic, resorption occurs but is delayed. It is evident that the underlying 
permanent tooth is imprisoned until, by a loss of overlying structures, 
it is free to move into position. Many of these dead teeth and dead 
roots are removed by a process similar to that which occurs in the cast- 
ing off of the useless roots of the permanent teeth ; a general resorp- 
tion of the provisional alveolar bone occurs, and the root is cast out; its 
separation from the soft tissues may again be accomplished by the pro- 
cess of suppuration. 

Treatment. — If a pulpless deciduous tooth be present in the 
dental arch when the corresponding permanent tooth of the opposite 
side of the jaw is in process of eruption, the pulpless tooth should be 
extracted. Prior to this time the deciduous tooth should be retained, 
provided, by appropriate antiseptic treatment, its pericementum can be 
brought to and be maintained in a healthy condition. The space 
between adjoining teeth occupied by the temporary teeth affords room 
for the accommodation of the permanent successors. Too early extrac- 
tion is followed by insufficient space. This is particularly notable fol- 
lowing premature loss of the deciduous second molars. 



SECOND DENTITION. 201 

Eruption of Molars. — It is rare that abnormalties are associated 
with the progress of the eruption of the first or second permanent 
molars. It may be noted in very rare cases that there is a failure of 
harmony in the development of alveolar and body bone ; that insuf- 
ficient space exists posteriorly for the accommodation of the second 
molars. They suffer more or less impaction, particularly in the lower 
jaw ; as a rule, subsequent development of the body of the bone affords 
the needed space. It is with the eruption of the third molars that 
aberrations are most frequently noted. 

Pathological Eruption of the Third Molars. — At the time 
of eruption of the permanent second molars, the third molars in both 
jaws occupy recesses in the alveolar bone and are in but a partial state 
of development. In the upper jaw these recesses occupy the tuberosity 
of bone bounded anteriorly by the distal walls of the second molars, and 
posteriorly by the tips of the pterygoid processes of the sphenoid bone. 
This rounded prominence grows larger as the development of the teeth 
proceeds. It is unusual that much lack of space exists for the accommo- 
dation of the tooth. Should the development of the tuberosity not keep 
pace with that of the tooth, and eruption proceed, the direction of erup- 
tion is outward toward the cheek ; the relations of the pterygoid pro- 
cess and of the palate bone with the tuber- 

. . Fig. 142. 

osity make a path of greatly increased resist- 
ance at the palato-alveolar angle ; backward 
eruption is prevented by the pterygoid 
processes ; direct eruption, by the second 
molar and pterygoid process, so that the 
path of least resistance is outward toward 
the cheek. It is occasionally noted that 

this tooth erupts with its Occlusal face Abnormal eruption of the upper 

pointed directly toward the cheek, a posi- 
tion at right angles to that it occupies normally (Fig. 142). In rare 
instances the upper third molar is caught between the second molar 
and the pterygoid process ; in such cases eruption is prevented or 
delayed (see Chapter X.). 

In cases of difficult eruption conditions may arise which tend to 
increase the morbid processes and to alter their character. There is, 
first, an irritative hyperemia of the soft tissues surrounding the erupt- 
ing tooth. As this is the region of the mouth least affected by dental 
cleansing agents used by the patient, and in which the irrigating office 
of the saliva is very incomplete, fermentation-processes are common ; 
their products added to a part in active hyperemia can but aggravate 
the condition. Pyogenic cocci, usual inhabitants of the mouth, may 
infect the tissues, finding with numerous other organisms a habitat 




202 DENTITION. 

between the tooth and the swollen gum-margin ; thus it is that pus- 
formation may accompany the delayed eruption. If the swollen parts 
be incised, and antiseptic sprays be directed into all of the recesses, 
a disappearance of symptoms is noted. 

It is in connection with the lower third molar more frequently than 
with any of the permanent teeth that pathological eruption is most com- 
mon. In civilized races the room for the accommodation of the crown 
of the lower third molar, between the distal wall of the second molar 
and the base of the inner root of the condyloid process, is frequently 
but scant ; the tendency of maxillary development is to render restricted 
space the rule rather than an exceptional occurrence. The crown of 
the tooth does not make its appearance until developmental changes 
have secured sufficient space for it. This may delay its eruption for 
months or years, and in some cases prevent eruption altogether. In 
others the development of the tooth may proceed after all develop- 
mental changes in the jaw have ceased, and the teeth are entirely encap- 
suled (see Chapter X., Impacted Teeth). The delay in eruption in 
the more severe cases is due to improper configuration of the bony sur- 
roundings ; the delay in milder cases may be due to imprisonment by 
soft tissues ; in other cases pathological conditions are caused not so. 
much by imprisonment as by irritation of the soft tissues. 

It is almost the rule that eruption of the lower third molars is 
attended by some degree of discomfort. Usually for some months 
before the cusps of the crown make their appearance through the gum 
there is an ill-defined uneasiness about the jaws and some stiffness of 
the muscles of mastication. These symptoms disappear and recur at 
irregular intervals until the crown is entirely through the gum. Inter- 
ference is rarely called for; the usual antiseptic mouth-washes employed 
by the patient guard against infection of the irritated parts. In 
cases where the gum presents a swollen and irritated appearance relief 
follows the application to the affected gum of iodin tincture. Should 
the mesial half of the crown be free and the posterior half covered by a 
curtain of gum, it is advisable that the pocket between the tooth and 
gum be eradicated, as it forms a recess in which the active causes of 
dental caries thrive, and in which fermentations arise, forming irritating 
products. In the more severe cases these may induce active inflamma- 
tion of the soft tissues to an alarming extent. In all of these cases 
where bands or curtains of gum-tissue are the cause retarding erup- 
tion the indication is to freely divide the tissue longitudinally. The 
precaution should be taken to spray the parts freely with an antiseptic 
before and after making the incision. The cutting may be rendered 
painless by slipping under the gum-flap for a few moments a pledget 
of cotton containing a 6 per cent, solution of cocain hydrochlorid, the 



SECOND DENTITION. 203 

same solution being painted over the flap. The incision is made with a 
pointed bistoury, its point being directed toward the crown. 

It is when some portion of the posterior segment of the crown is 
held back by bony tissue that the more severe symptoms appear, usually 
in the degree of bony imprisonment. The general character of the 
pains in these cases is heavy and rheumatic, indefinitely located about 
the angle of the jaw and the ear. Combined with pain is usually 
marked stiffness of the masseter muscle ; in the more severe cases the 
spasmodic contraction of the muscle may simulate trismus of that side. 
These symptoms may appear irrespective of any marked evidences of 
inflammatory reaction of the tissues around the imprisoned crown. The 
pains are of the type called periosteal — dull, gnawing, heavy. 

The pockets between gum and tooth-crown offer passageways for 
infection of deeper tissues, so that it is not surprising, particularly in 
unclean mouths, that inflammation and suppuration of the tissues about 
the part may occur. The inflammatory process may extend to the neigh- 
boring soft tissues ; there is usually increased rigidity of the masseter 
muscle, so that it is with the utmost difficulty that the mouth can be 
opened even with mechanical assistance. It is not unusual, therefore, 
as a result of inability to reach the parts for local therapeutics, for 
suppuration to extend far beyond the original focus of irritation. 
Relief is not attainable until free vent for the pus is given, the dis- 
charge being often through the cheek. 

Treatment. — Nowhere more than here does the dictum of surgery 
— remove the source of irritation, apply. The source of irritation 
common to all of the cases being the tooth for which there is insuf- 
ficient room, the general indication is its extraction. This operation 
is, however, frequently attended with difficulties which render it in 
some cases highly impracticable. In the least severe cases of bony 
imprisonment, if untoward symptoms can be held in abeyance for some 
months, the obstruction to the tooth's advance may be removed and 
eruption be completed. The principal object during the period of delay 
is to prevent infection of the parts, so that antiseptic mouth- washes play 
an important part in the treatment. Local irritation may be largely 
allayed by the free application of tincture of iodin diluted with alcohol. 

If the rheumatic pains about the jaw and neck and the stiffness 
of the masseter muscle be of moderate degree, relief is afforded by 
free massage of the parts. If the pains assume a neuralgic character, 
much relief may be secured through the use of sedative ointments, such 
as those of aconitia and veratria. 

1^. Aconitia, gr. j ; 

Cerat. simp., 3j. — M. (Flagg.) 



204 DENTITION. 

In making this ointment it is to be manipulated so that it is 
certain the drag is evenly distributed throughout the cerate. A 
minute portion of the ointment is rubbed over the masseter mus- 
cle in front of the ear and about the angle of the jaw by means of 
the finger. 

Flagg commends the efficacy of an ointment of veratria when that 
of aconitia fails to procure relief: 

1^. Veratria, gr. xx ; 

Cerat. simp., 3j. — M. (Flagg.) 

S. Used in the same manner. 

It should be noted that both of these ointments are actively poison- 
ous, and should be kept from absorbent surfaces. 

Should severe symptoms arise, extraction is imperatively demanded, 
and had best be done before increasing stiffness of the muscles inter- 
feres with the proper opening of the mouth. In some cases there is 
no doubt of the practicability of extracting the third molar ; when the 
crown is freely exposed and not decidedly imprisoned by the coro- 
noid process, forceps may grasp it firmly and by an inward and upward 
rotary movement the tooth is extracted. In cases of more decided im- 
paction, the resistance oifered outwardly by the external root of the 
coronoid process, backward by the internal root of the same, and for- 
ward by the second molar, may render extraction impossible without 
the previous removal of some portion of the bone. It is evident that 
in such a case attempts at forcible extraction would be inevitably fol- 
lowed by fracture of bone or of the tooth, the latter occurring more 
frequently than the former. It is advisable — indeed, almost neces- 
sary — in such cases that the second molar be the tooth extracted. This 
applies also to the cases of more decided imprisonment with active 
inflammation. 

Where stiffness of the masseter muscle fixes the jaws so that they 
cannot be separated sufficiently to secure a grasp upon either the third 
or even the second molar, mechanical violence may be necessary to sepa- 
rate them. A jaw-separator is placed in position, the patient etherized, 
and the separator operated until sufficient space is gained to secure a 
grasp upon the tooth ; failing the third molar, grasping the second molar. 
The muscle is sometimes of board-like hardness, and resists the force 
of the separator. Indeed, such resistance may be offered that separa- 
tion can only be effected by fracture of the muscle or of the bone. In 
these cases an antiseptic spray — hydrogen dioxid — is directed against 
and about the third molar for a period of ten minutes or longer ; as 
soon as sterilization is assured a curved bistoury is used to divide the 



SECOND DENTITION. 205 

swollen gum-tissue about the tooth, and cold compresses are placed over 
the angle of the jaw. The antiseptic spray is subsequently applied at 
intervals of about two hours. If local massage be practised in addition, 
the swelling and muscular hardness usually disappear in a few days, 
when the jaws may be separated sufficiently to allow extraction of the 
molar (see Impaction of Teeth, Chapter X.). 



CHAPTER X. 

MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

In the majority of persons the entire denture consists of thirty- 
two teeth arranged in two parabolic curves, one upper and one lower, 
each semi-denture having sixteen teeth. Normally both the upper and 
the lower teeth are bilaterally symmetrical, the eight teeth of either 
half of the upper or lower denture corresponding exactly in size, form, 
and position with the corresponding eight teeth of the opposite side. 
Each tooth of each upper and lower eight, while diifering in size and 
details of form from all of its fellows, yet bears a definite relationship 
to each of the others as regards size. 

Abnormalities of the teeth are found associated with position, size, 
form, and structure. Aberrations in form, structure, and size are in- 
cluded under the head of malformations of the teeth ; aberrations of 
position are discussed under the head of malpositions of the teeth. 
The particular section of dentistry relating to malpositions of the teeth 
is by general consent made a special department of operative dentistry, 
that of orthodontia ; but many of the phases of the subject are of great 
pathological interest, although the therapeutic measures usually de- 
manded are mechanical in character and clearly belong to the fields of 
operative and prosthetic dentistry. 

Malformations of the Teeth. 

Malformations of the teeth may be either macroscopic or micro- 
scopic ; they may be evident to the unaided eye, or may require for 
their detection special preparation for observation under the microscope. 

MICROSCOPIC MALFORMATIONS. 

Microscopic or histological defects of the teeth may affect any of the 
dental tissues, enamel, dentin, cementum, pulp, or pericementum. 

Enamel. — Defects in enamel-structure range from any degree of 
orderliness in the even distribution of globular bodies and cementing- 
substance in the tissue to gross aberrations in formation. The finer 
variations of structure are not easily recognizable. 

Theoretically perfect enamel should show in longitudinal section a 
series of squares of uniform size built into rods, the spaces between the 
squares and rods being marked by lines of cementing-substance having 

206 



MALFORMATIONS OF THE TEETH. 



207 



a refractive index slightly different from that of the squares. While 
such a structure is perhaps never found, it is difficult to draw a line 
where aberrations from such a standard become pathological. An arbi- 
trary standard might be assumed as follows : regard any enamel as 
pathological where areas of it differ from its general substance to such 
an extent as to have a decidedly different refractive index. A typical 
form of abnormality is noted in what are known as white spots of the 
enamel, areas in which an opaque surface exists instead of the normally 
translucent enamel. 

In Fig. 143 is represented a magnification of 500 diameters of a 
section made of a portion of a white spot where it adjoins normal 

Fig. 143. 





Margin of section through " white spot." X 500. (Williams.) 



enamel. The area of white spot when viewed by transmitted light 
shows dark in the section. The enamel of the white spot is more or 
less granular in structure, and its globules are not fused together in rods 
as in normal enamel. Williams suggests as an explanation of this con- 
dition that there is a deficiency of the cementing-substance. 



208 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

Fig. 144. 




Anteroposterior section of human lower molar, showing defects of structure in the vicinity 

of sulci. X 12. (Williams.) 

Fig. 145. 




Section of human molar, showing dentinal fibrillae penetrating enamel. X 600. (Williams.) 






MALFORMATIONS OF THE TEETH. 



209 



Enamel-formation about the sulci of teeth is frequently faulty ; 
owing to an imperfect union of the enamel-segments forming the cusps 
of the teeth minute fissures exist in the enamel ; these are most marked 
in the fissures of molars, as shown in Fig. 144. The enamel bounding 
these fissures has an irregular structure. 

The dentinal fibrillar may penetrate the substance of the enamel 
(Fig. 145), occupying defined channels in its substance ; this is a 
developmental accident. Williams points out that the organic filaments 
from the dentin become atrophied with the progress of enamel-formation 
and canals remain. The probable explanation of this condition is that 
a process of an odontoblast prior to enamel-deposition finds its way 
through the soft pre-enamel-deposit, and enamel-deposit encloses it, 
calcification occurs, and a permanent defect results. This condition, as 
also many other variations of structure found in the dental tissues of 
man, are shown by Williams to have their normal prototypes in the 

Fig. 146. 




Section of human bicuspid, showing mass of very imperfectly calcined enamel projected into the 
dentin, with coarse fissures leading to the surface. X 75. (Williams.) 



dental tissues of lower animals ; for example, the penetration of den- 
tinal fibrillar into enamel is a normal condition in the teeth of the kan- 
garoo. The presence of organic tissue in the enamel of man is, how- 
ever, always to be regarded as pathological. Such conditions are not 
to be confounded with fissures of enamel where large lines of faulty 
calcification or non-calcification extend through the thickness of enamel 
(Fig. 146). 

14 



210 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

Enamel, even normal enamel, is not of uniform composition ; were 
it so, it would exhibit, in addition to an orderly arrangement of its his- 
tological elements, a uniformity in color. So common are differences in 
this direction that the presence of pigment-bands must be regarded as 
normal. It is the rule to find enamel traversed by deeply pigmented 
parallel bands (Fig. 147) which pass obliquely upward from the surface 



Fig. 14 




Section of human incisor, showing " bands of Retzius " and marked stratification of 

enamel. X 125. (Williams.) 

of the dentin to the surface of the enamel. These are termed the 
bands of Retzius (see Chapter VII.) ; they appear to mark the size 
of the enamel-cap at successive periods of its growth. 

Stratification and striation of the enamel, as shown by Williams, must 
be regarded as normal physiological records of the mode of enamel- 
formation. 

All of these histological defects represent variations of deposition, of 
formation, no doubt due to fluctuations of the nutritive processes of the 
child at the time of tooth-formation. Histological records made in 
the enamel are not like those made in other tissues, for there is no 
nutritive provision through which such defects can be remedied at 
subsequent periods. 

Profound nutritive disturbances, such as those attending hereditary 
syphilis in children, affect the structures of the teeth. One of the gross 



MALFORMATIONS OF THE TEETH. 



211 



results of this disease is a common malformation of the general form of 
the incisors. The hard tissues of such teeth exhibit microscopic evi- 
dences of faulty histology ; they are dull and opaque and traversed by- 
irregular bands. Viewed in section the enamel of such teeth is seen to 
be almost structureless (Fig. 148). Williams found that the contents 

Fig. 148. 




Section of enamel from syphilitic tooth, with appearances resembling the lacuna? of cementirm. 

X 600. (Williams.) 

of the large irregular spaces in this enamel did not respond to stains — 
i. e., did not contain organic matter. 

There is evidence that other forms of specific dermatitis — scarlet 
fever and measles — which occur at an early age may atfect the forma- 
tion of enamel. The defects attrib- F IG 149 
uted to the exanthemata are irregular 
pits upon the crowns of, particularly, 
the incisors (Fig. 149). With a history 
of a case, including the age of the child 
at the period of the disease, if exam- 
ination be made of the positions of 
the defects, the age will serve as an in- 
dication as to whether there has been any connection between the eruptive 
fever and the dental malformation. For example, if enamel-pits upon 
incisors have been caused by an eruptive fever between the ages of four 
and five, they should occupy about the half-way area of the crown-face ; 
it is evident that the enamel being already formed about the cutting-edge 




w .1 mc_j[^ 

Teeth of eruptive fevers. 



212 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 



Fig. 150. 




of the tooth, alterations of nutrition could not affect the already formed 
tissue. In cases where a causal association of enamel-defects with the 
eruptive fever is made out with reasonable clearness it is usual to 
find all of the crowns of the teeth which are in process of formation 
affected in a similar manner. The defects and pittings are so pronounced 
in some of these cases as to give a general honeycombed appearance to 
the crowns ; such teeth are known in dental parlance as " honeycombed 
teeth." 

Cases are observed where there has been a formative crisis to the ex- 
tent of having no enamel whatever formed over the occlusal section of 
the crown, its deposit on the remainder of the crown being 
quite normal (Fig. 150). 

D. B. Freeman l records the case of an individual, aged 
twenty-six years, whose teeth anterior to the second molar 
were entirely devoid of enamel. The condition was hered- 
itary, it appeared in both brothers and sisters, and could be 
traced back for three generations. 

Dentin. — Data regarding the finer phases of defective 
histological structure of the dentin are meagre. It has been observed 
that the dentinal tubuli of some teeth are much larger than in others 
of the same age, and, no doubt, future investigations with an improved 
technique directed toward a study of the exact mode of den tin-formation 
will exhibit defects more certainly. 

The chief histological defects noted in dentin are areas of faulty or non- 
calcification, called interglobular spaces (see Chapter VII.). These are 

most common in the dentin immedi- 
ately underlying its covering tissue, so 
common in the dentin under the ce- 
mentum that this portion of dentin 
has been called the stratum granulo- 
sum, the granular layer of Tomes (Fig. 
151). In the body of the dentin these 
spaces have a more irregular distri- 
bution. 

In wet ground-sections (Rose) the 
dentinal filaments are seen to pursue an unbroken course through these 
areas. The contents of the interglobular spaces react to stains like 
the sheaths of Neumann; that is, they probably contain transitional 
tissue. These areas probably represent, as do defective spots of enamel, 
periods of depressed vitality or of altered nutrition. In the light of 
present knowledge regarding the subject they are to be viewed as areas 
in which the calcific process was faulty. The malformations noted in 

1 See Guilford, American System of Dentistry^ vol. iii. 



Fig. 151. 




Dentinal tubuli terminating in the spaces of 
the granular layer. (Tomes.) 



MALFORMATIONS OF THE TEETH. 



213 



connection with the enamel of syphilitic teeth have their analogues in 
the dentin (Fig. 152). 

Histological congenital malformations of the pulp have not been 



Fig. 152. 




Section showing interglobular spaces in dentin of a syphilitic human tooth. (Williams.) 

Fig. 153. 



mi 




Section of a bicuspid with its alveolus, showing a pit-like absorption upon the side of the 
root in which the redeposit of the cementum has begun : a, dentin ; b, cementum ; c, peri- 
dental membrane ; d, bone forming the wall of the alveolus ; e, absorbed area of cementum. 
It will be noticed that a new deposit of cementum has begun the filling of the area, and that 
the soft tissue in the area of absorption is of a cellular type. The bone also shows the effects 
of absorption in the cutting away of portions of the rings of the Haversian systems at /, while 
at g the presence of osteoclasts shows that absorption is in progress at that point. (Black.) 

recorded, the normal histology of the organ not being made out with 
sufficient certainty to determine what appearances are to be regarded 



214 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

as abnormal. Grosser aberrations, such as those shown in Fig. 103, 
are made out. 

Cementum. — As stated in Chapter VII., the pericementum con- 
tains numbers of multinucleated cells — odontoclasts ; and their presence 
is not to be regarded as abnormal. The cementum of the roots of teeth 
may exhibit evidences of former action of these cells in excavations of 
cementum which by a subsequent deposition of cementum have become 
filled. This gives an irregular course to the cement-laminae (Fig. 153). 
These appearances are to be regarded as not necessarily pathological, 
for the following reason : for some time (years) subsequent to the erup- 
tion of the teeth developmental changes occur in the alveolar bones, 
depositions (subperiosteal) increasing their volume, are accompanied by 
resorption of other portions of the bone, such a balance being kept 
between the processes that the teeth, although shifting their positions, 
are kept in normal occlusion. 

MACROSCOPIC MALFORMATIONS. 

The teeth may vary from normal either as regards size or external 
configuration. 

Variations as to Size. — It is patent to the most casual observer 
that the teeth vary as to size. Comparisons in this direction are made 
by an examination of the upper central incisors. Fig. 154 shows nearly 
the extremes of observable sizes ; Guilford x points out that excessively 
large central incisor-crowns are usually supported by abnormally small 
conical roots. Marked giantism of the central incisors usually occurs 
in pairs, the other teeth being of normal size. On the other hand, den- 
tal giantism of less degree may involve all of the teeth of a denture. 
The molar teeth are occasionally of enormous size, the bicuspids rarely 
so, and the cuspids next in frequency to the molars as to the occurrence 

Fig. 154. Fig. 155. 




of giantism. Guilford observes that giantism of the cuspid-crowns, 
unlike that of the central incisors, is usually accompanied by a corre- 
sponding size of root. He mentions the case of a cuspid measuring 
an inch and a half in length from tip to tip. 

1 American System of Dentistry, vol. iii. 



MALFORMATIONS OF THE TEETH. 



215 



Dwarf Teeth. — Deficiency in size is of more common occurrence 
than excessive size. It appears to occur more frequently with the upper 
third molars and upper lateral incisors than with any other teeth. The 
accompanying figure (155) shows the extremes in size between two per- 
fectly formed lower third molars. The stunting of these and of other 
teeth is, however, usually associated with such an aberration of outward 
form that most dwarf teeth must be considered as abnormal in form as 
well as in size. 

Abnormalities of Form. — It is in the outward forms of teeth that 
the greatest aberrations are met with. These range from a slight exag- 
geration of one or more of the architectural elements of a tooth to such 
malformations as produce an entire unlikeness to all tooth-forms — to 
masses which cannot be properly classified as teeth. The most common 
of these malformations is an irregularity of cusp-form ; cusps are sup- 
pressed or are but primitive. A survey of the primal basis of tooth- 
forms reveals that most of these malformations are due to improper 
modifications or combinations of the formative cones. A common type 
is one or more of the incisors, most frequently the lateral incisors (Fig. 
156), presenting as unmodified cones or as conical masses, the normal 
form, it will be recalled, being a truncated and compressed cone. 

Fig. 156. 




Next in point of frequency, the upper third molar is seen to consist of 
but a single cone instead of three fused cones. At the other extreme the 
primitive cones may be so combined as to produce such irregularities of 
cusp and sulcus arrangement that the masses have lost all semblance to 
normal tooth -forms. 

Pitted and Grooved Teeth. — The effects of profound disturb- 
ance of the course of nutrition upon the histological structures of the 
teeth have been described. Such teeth are also affected as to their out- 
ward form. The malformations may consist of series of irregular 
grooves and pittings, the crowns having the general normal outlines ; 



216 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

or, again, the form of the tooth itself may be altered (Fig. 157). 
A single groove across the face of a tooth represents, no doubt, a 
period of nutritive disturbance, but cases are seen where there is a 
repetition of grooves separated by ridges of apparently normal enamel, 
indicating waves of nutritional disturbance, as shown in Fig. 157. The 
defective formation may be confined to one portion of the crowns of 
the teeth, most commonly the occlusal half of the first permanent molars 
and of the incisors. 



Fig. 157. 



Fig. 158. 






Fused molars. 
Fig. 159. 




Showing the front teeth grooved from the alterna- 
tion of perfectly and imperfectly developed 
portions of enamel. (Tomes.) 



Permanent central and lateral in- 
cisors of the upper jaw, united 
throughout the whole length of 
the teeth. (Tomes.) 



Fused Teeth. — It is occasionally observed, more frequently with the 
upper second and third molars than with other teeth, that, instead of two 
separate teeth terminating the dental series, its extremity is occupied by 
a large dental mass, which upon examination shows the cusp-elements 
of both the second and third molars present. Upon extraction this 
mass is seen to form but one tooth, but an anatomical analysis clearly 
reveals its dual character ; its anterior portion corresponds with a second 
molar, its posterior with a third molar. The root-arrangement also 
indicates a fusion of two teeth (Fig. 158). The anterior teeth may be 
united after the same manner (Fig. 159). It will be observed that this 
union is most likely to occur where the adjacent tooth-follicles have 
least anatomical separation from their fellows ; it is most common be- 
tween incisors and incisors, incisors and cuspids, and second and third 
molars. It appears not to have been observed in connection with the 
bicuspids, the crowns of these teeth during the formative stage being 



MALFORMATIONS OF THE TEETH. 



217 



confined between the roots of the temporary molars. The follicles of 
teeth liable to fuse depend for separation from one another upon the 
formation of bony walls. 

A histological examination of these teeth exhibits a pulp-cham- 
ber, which may be common throughout, or, as more frequently hap- 
pens, distinct and separate root-portions of the pulp are observed. 
The malformations of the crowns are clearly traceable to the fusion of 
the lateral walls of the enamel-organs before or soon after enamel- 
formation begins, because it is found that these teeth have a common 
pulp-chamber. If the fusion occurred subsequent to the first deposition 
of calcic substances, the pulp-chamber would be double. In the period 
of root-formation the common pericementum may or may not be 
divided ; if it is, the fused crowns are associated with separate roots ; 
if not, the roots are fused and have dentin common to both throughout. 

Concrescence of Teeth. — Concrescence of teeth is their union 
after the tooth is formed ; it is evident, therefore, that the union can 
only be caused by fusion of cementum. This means that at some por- 
tion of the formative and eruptive period the bony partition between 
the teeth disappears, and that their pericementi become united, receding 
from the line of compression as cementum is deposited between and 
joining the roots. 

In the eruption of the third molars, particularly the upper, tem- 
porary lack of space for the eruption of the crown may cause absorp- 
tion of the bone covering the roots of the second molar, and fusion of 
the formative pericementum of the third molar with that of the second 
occurs ; a deposition of cementum then binds the teeth together, prevent- 
ing the eruption of the third molar. 

Geminous Teeth. — These have been termed twin teeth, in contra- 
distinction to fused teeth. In twin teeth the enamel-organ, developed 



Fig. 160. 



Fig. 161. 





—a 



s a 

Fig. 160.— The upper molar. 

Fig. 161. — Showing unusual development of the cingule or basal talon on an incisor, 
case reported by W. H. Mitchell, Dental Cosmos, vol. xxxiv., p. 2036.) 



(From 



from some single cord, assumes the form of two teeth, and the tooth 
developed in such enclosure has the form of a duplicated prototype. The 
second segment is to be classified as a supernumerary mass. 



218 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 



Supplemental Cusps.— It is occasionally observed that a tooth 
has a greater number of cusps than normal. The most common form 
of this condition is a supplemental mass attached to the palatal side of 
the mesio-palatine cone of the upper first molars (Fig. 160). The 
palatal tubercle, the prominence upon the cingule of an upper incisor, 
may be of exaggerated size. In one case recorded (Fig. 161) this 
development gave the appearance of a talon upon the tooth, a distinct 
cusp-segment in itself. 

Malformations of Roots. — Differences in regard to the size, 
arrangement, forms, and number of the roots of teeth are the most 
common of dental malformations. The roots of teeth may be abnor- 
mally short ; they may be inordinately long — roots of cuspid teeth more 
than an inch in length are by no means uncommon (Fig. 162 ). The roots 
of cuspid teeth may be bifurcated (Fig. 163), and those of bicuspids 
trifurcated (Fig. 164). The lower molars may have three roots (Fig. 
165). Thompson 1 has pointed out that such malformations, together 



Fig. 162. 



Fig. 163. 



Fig. 164. 



Fig. 165. 







Upper cuspids. 



Upper first bicuspid. 



Lower first molar. 



with certain crown malformations, are instances of zoological atavism. 
Abnormalities of root-forms are of extreme frequency. Examples of 
these are seen in Figs. 166-177. 



Fig. 166. 



Fig. 167. 



Fig. 168. 



Fig. 169. Fig. 170. 





. -1 




> i /Mm! 

if 

1 ■KSr 




tX% 




H 


iSiiis 


Lower 


bicuspids 



Upper molars (Ottolengui). 

Hutchinson Teeth. — Attention was first called to, and an ade- 
quate explanation of the condition given by Jonathan Hutchinson, as to 
the effect of hereditary syphilis upon the permanent teeth. He observed 
in the children of syphilitic parents a malformation of the anterior 

1 American Textbook of Operative Dentistry. 



MALFORMATIONS OF THE TEETH. 



219 



teeth, the incisors commonly and inconstantly the cuspids. The situ- 
ation of these malformations is such as to correspond to that period of 



Fig. 171. 



Fig. 172. 



Fig. 173. 





Abnormalities in teeth. 




Fig. 174. Fig. 175. 



Fig. 176. 



Fig. 177. 






development when the evidences of hereditary syphilis are noted in the 
infant. 

Confusion of description by dentists and faulty observation by 
medical practitioners as to both forms, have led to much confusion 
as to what particular forms of teeth are to be regarded as syphilitic. 
The teeth most frequently aifected are the upper central incisors. It 
will be recalled, in this connection, that children of syphilitic parents 
have usually a tardy eruption of the deciduous teeth. The teeth have 
a dull, opaque color. The central or lateral incisors upper and lower, 
either, both, or any of them, have, instead of the normal angles and 
flattened curves of the labial faces, a roughly rounded and stunted ap- 
pearance ; the occlusal edge of the tooth is narrower than its neck. Over 
the tips of these stunted and conical teeth the enamel is irregularly and 
badly formed ; but there is a semblance of the three enamel-tubercles 
found normally. The middle tubercle appears to be of the most defec- 
tive enamel (Fig. 178), because it is soon lost by abrasion, leaving a 
notch in the tooth at its former site (Fig. 179). While Hutchinson 
regarded the central incisors as the diagnostic teeth of hereditary 
syphilis, all of the teeth undergoing amelification at the same time may 
exhibit deformities, one of the most frequent being the malformation 
of the cuspids. 

It has been noted that not all children who are the victims of 
hereditary syphilis present these dental appearances ; and, again, ap- 



220 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 



pearances said to be identical with them are observed in children said 
not to be syphilitic ; nevertheless the presence of such teeth is usually 
regarded as a valuable diagnostic sign of hereditary syphilis. Thera- 




Fig. 179. 




Syphilitic teeth in upper and lower jaws as 
they appear when recently erupted. 



The teeth of hereditary syphilis 
at maturity. 



peutic measures based upon this, as well as other doubtful indications, 
are followed by better results, perhaps, than when the general indication 
of the dental malformation is ignored. 

The existence of interstitial keratitis is accepted as additional diag- 
nostic sign of hereditary syphilis in the infant. 

Odontomes. — In rare cases dental masses of such irregular form 
as almost to defy classification make their appearance in the dental arch. 
They may appear instead of the teeth, in addition to them, or after 
them ; such masses may be grouped under the head of odontomes. In 
some instances they never make their appearance in the dental arch, 
but may remain imbedded in the substance of the jaw for lengthened 
periods ; here they may give rise to cyst-formations (called odontoceles)? 
may excite no evident reaction, or may be the exciting cause of various 
morbid reactions. 

In some instances the fusion of two teeth may produce a mass of 
such irregularity of form as to give the appearance of a dental tumor, 
but critical examination rarely fails to demonstrate a fusion. Equally 
odd appearances may result from the fusion of supernumerary with 
the normal teeth (Fig. 180). The nature of these cases may usually be 

made out by the more or less 
orderly arrangement of cemen- 
tum and enamel (Fig. 181). 
A specimen (Fig. 182) in the 
museum of the Academy of 
Stomatology of Philadelphia, 
shows two masses making their 
advent between the upper cen- 
tral incisor teeth, forcing these 
teeth aside. From the appearance of the surfaces of these masses they 
represent the results of a plication of the surface of the enamel-organ from 



Fig. 180. 



Fig. 181. 





A supernumerary tooth attached 
to the roots of an upper molar, 
the supernumerary tooth being 
inverted. (Smale and Colyer.) 



MALFORMATIONS OF THE TEETH. 



221 



which they derived their enamel. Clearly they are the results of the for- 
mation of two adventitious dental cords. Fig. 183 illustrates an odon- 



Fig. 182. 




Fig. 183. 



toma in which the dental nature of the growth is to be clearly made 
out; the enamel-forming organ from which the mass derived its enamel- 
cup was of anomalous form. Such specimens are known as warty teeth 
(Salter). 

Broca 1 was the first to offer a systematic classification of tooth- 
tumors, although the connection between various tumor types and dental 
tissues had long before been made out. 

The discussion of the pathogenesis, clinical history, and treatment of 
odontomes which arise from some portion of the tooth-follicle in its 
embryonic state and cause the formation of exten- 
sive neoplastic growths which bear no resemblance 
to tooth-forms, their only points of association 
being scattered histological appearances, belongs to 
the province of general surgical pathology, and 
their treatment to general or special surgery, so that 
they can be fitly dismissed from these pages with a 
brief mention. 

A developed tooth-follicle contains within it 
both epiblastic (epithelial) and mesoblastic (con- 
nective) tissue-elements. An aberrant, morbid tissue-development may, 
therefore, give rise to either epithelial or connective-tissue new forma- 
tions, the cellular elements of which may be of an embryonic (sarco- 
matous) or mature (fibromatous, osteomatous, etc.) type ; or may be the 
starting-point of either comparatively benign epithelial growths or even 
of carcinoma. The growth may contain the elements of several types 

1 Recherches sur une nouveau groupe de tumeurs designe sous le nom d' odontomes, 1867. 




Odontoma. (Garretson.) 



222 MALFORMATIONS AND 3IALF0SITI0NS OF THE TEETH. 



combined. It appears that cyst-formation most commonly results from 
a continued collection of fluid between the epithelial coating of a tooth- 
follicle and the dentinal and enamel elements underlying, the accumula- 
tion of fluid causing the formation of a sac lined by the transformed 
epithelial wall. 

Odontomata of direct clinical interest to the dental practitioner 
are those connected with some portion of a tooth, showing an irreg- 
ular or anomalous growth of some one or more of the dental tissues. 

Fig. 184. Fig. 185. Fig. 186. 






Enamel excrescences. (Salter.) Results of hernia of a pulp. (Salter.) 

Many of these may be and have been classified under the head of mal- 
formations of the teeth. Many of the surgical odontomata exhibit but 
slight trace of any dental structure, but in the class under discussion it is 

Fig. 187. 




Fiar. 186 magnified. 



evident that a continuous relationship has been kept between an enamel- 
organ, a dentinal pulp, and a cementoblastic structure, even though the 
aberrations of tooth-form and of limitations as to extent of growth 



MALFORMATIONS OF THE TEETH. 



223 



diverge widely from the normal. In some of these growths it is 
evident that tooth-development has progressed in an orderly manner to 
a varying degree before any aberration of development occurred ; in 
others it is evident that development has been aberrant from the 
beginning. 

The growth may be associated with enamel, dentin, or cementum 
development ; and its tissue-elements as regards the dentin may remain 
normal, or may occasionally partially revert to other types, vaso- 
dentin, osteodentin, etc. Figs. 184 and 185 exhibit the results of 
activity of the enamel-organ continued after its normal formative period 
and in an irregular manner. 

The development of both enamel and dentin may proceed in an 
orderly manner for some time, when an irregular developmental impulse 
arises in the dentinal pulp, leading to its enlargement and extension 
beyond the enamel-organ, which latter structure suffers atrophy, and a 
growth of the following type results. The pulp outgrowth may not 
occur until both crown and root of the tooth have 
been formed in an orderly manner, when a hyper- 
trophic impulse causes this organ to extend far 
beyond its normal boundaries, still, however, en- 
closed in the follicular wall ; the pulp in its new 
relations deposits dentin, over which cementum is 
deposited (Figs. 188, 189, and 190). 



Fig. 189. 



Fig. 188. 



i) 





Figs. 188 and 189.— Results of pulp-hernia. (Tomes.) 

Neither the enamel-organ nor dentin-pulp may assume its normal 
type, and yet the relationship between the epithelial tissue of the 
enamel-organ and a layer of odontoblastic cells in the underlying meso- 
blastic tissue is maintained, together with a general enclosure in a 
follicular wall, in which event an irregular mass (see Fig. 183, warty 
tooth) containing the dental elements is formed. 

Irregularity of growth is undoubtedly more frequently associated 
with the cementum than with any other dental tissue. It may assume 
the form of a generally excessive deposit, be in the form of a nodule 
or nodules, or be a large irregular mass. 

Treatment. — The treatment of these cases is that applied to all 



224 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

removable tumors — radical extirpation. While in some cases this con- 
sists of the operation of tooth-extraction on a large scale, in others the 



Fig. 190. 




A section of Fig. 189 through A B. 

removal of an odontome involves the performance of a surgical opera- 
tion of some magnitude. 

Anomalies of Number. — Although the dental series of man nor- 
mally consists of thirty-two members, cases are frequently observed 
where the number is in excess of or less than that number. 

Deficiency. — It is observed with some frequency that the upper 
lateral incisors of a denture never make their appearance, a condition 
traceable to the influence of heredity in some of the instances. The 
permanent cuspids erupt and occupy the lateral incisor space. The 
third molars may never appear ; instead of being represented by a rudi- 
mentary tooth, they are apparently never formed. There is no doubt 
that in some of the cases of apparent absence of the third molars that the 
teeth may be encysted in the maxillae ; but when none of them appear 
up to the age of forty years it is a fair inference that they have not 
been formed. The writer has seen an upper third molar erupting at 
the age of sixty. The cases of suppressed teeth next in point of fre- 
quency are those of the bicuspid teeth. If, however, the corresponding 
teeth are all present in the dental arch, a well-founded suspicion of 
impaction of the missing tooth may be entertained. 

The extreme of suppressed formation is represented in a case de- 
scribed by Guilford. 1 A patient over fifty years old had never erupted 
any teeth, deciduous or permanent ; the alveolar arches revealed no evi- 
dences of enclosed teeth, but had the appearance of typical edentulous 
jaws ; the alveolar bone itself was primitive. The case appeared to be 

1 American System of Dentistry, vol. iii. 



MALFORMATIONS OF THE TEETH. 225 

sporadically hereditary, a grandparent and an uncle exhibiting a like 
condition. The cases are interesting also because of additional evidences 
of faulty evolution of dermoid structures. In the first case cited no 
sudoriparous glands appear to have formed, and there was but a faint 
growth of hair on the cranium, and none on the face and body. The 
uncle was hairless and edentulous from birth. Guilford found in other 
members of the family an absence of the full complement of teeth. 

Excess. — The possible occurrence of a condition in some respects the 
reverse of the preceding has been much written of and discussed — i. e. } 
the occurrence of a complete third denture. There can be but one con- 
clusion from an examination of all the evidence thus far presented, and 
that is that no clear and well-authenticated cases are made out. Isolated 
cases of the appearance of teeth subsequent to the loss of all of the sec- 
ond denture are not infrequent ; and, so far as clear records can be ob- 
tained, are resolvable into cases of the eruption of supernumerary teeth. 
While these cases are, at least for the present, to be held as unproved in 
connection with elderly persons, a well-authenticated case of multiple den- 
tition in a child is recorded by Catching. 1 Between the sixth and the sev- 
enth month the eruption of one set of teeth was complete ; within three 
months all of these had been lost. Between the eleventh and fifteenth 
months another period of dentition occurred, the teeth of this second 
denture being of such faulty structure as to crumble away quickly. At 
the age of two and one-half years a third dentition appeared, which 
caused the child such inconvenience that the teeth were extracted by 
the mother. At the age of eleven years a fourth series erupted, incom- 
plete through the absence of six teeth. At the age of fifteen these teeth 
were sound and firm. 

Fourth Molar. — The molar series of man, particularly in the 
lower negroid races, may consist of four instead of three members. 
When the fourth molar appears in the white races it is usually as a 
stunted member, a conical or peg-like tooth, similar to that which oc- 
casionally replaces the third molar. There is rarely room posterior to 
the distal wall of the third molar for their eruption, so that they make 
their appearance in the region shown in the illustration. S. M. Hart- 
man, 2 L. D. S., of Victoria, B. C, has furnished the model (Fig. 191) 
of a case where the molar form of the fourth tooth is unusually well 
pronounced. 

Supernumerary Teeth. — Any teeth in excess of the normal 
thirty-two, although clearly cases of reversion of type in many in- 
stances, 3 are included in the category of supernumerary teeth. Super- 

1 Southern Dental Journal, Oct., 1886. 2 Dental Cosmos, 1891. 

* A. H. Thompson, American System of Dentistry, vol. iii., and Kirk's Operative 
Dentistry. 
15 



226 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

numerary teeth appear as simple unmodified cones, or as combinations 
of cones resembling the forms of teeth. The conical form is most 
common. Cases where these peg-like teeth appear around the third 
molars singly or in number are numerous. Their appearance in any 

Fig. 191. 




situation is evidence that the normal number of dental cords has been 
exceeded. They are perhaps all to be regarded as cases of long rever- 
sion, not alone because they increase the number of the dental series, 

Fig. 192. 




but because they have primitive forms, a modification of the forms 
found among the reptiles and fishes. 

Guilford 1 divides supernumerary teeth into those having typical 
anatomical forms and those having the conical form. 

1 American System of Dentistry, vol. iii. 




MALPOSITIONS OF THE TEETH. 227 

Supernumerary incisors in either jaw having typical forms are not 
uncommon. In the upper jaw supernumerary centrals and laterals 
both appear, the latter more frequently (Fig. 192). Supernumerary 
teeth may occupy any position relative to the dental arch, but are more 
frequently seen at its lingual side. The compound cone occasionally 
appears (Fig. 193). In addition to molars and incisors, 
supernumerary bicuspids are occasionally found ; super- 
numerary cuspids are very rare. 

Unless supernumerary teeth are a source of offence 
either through their positions or appearance, they need 
not be disturbed. If they are found to be so, they may 
be extracted. 

Malpositions of the Teeth. 

A tooth is said to be in malposition when it is not in normal relation 
with the dental arch to which it belongs and to its antagonizing teeth 
of the opposing arch. Teeth are found in abnormal positions as the 
result of a variety of causes. Some of these operate prior to, during, 
or immediately after eruption ; some long after the eruption of the teeth, 
and some because of non-eruption. 

Malpositions which are remediable through the application of me- 
chanical force applied by means of suitable apparatus belong to ope- 
rative dentistry, as has been stated. They are fully treated of in works 
upon operative dentistry l and orthodontia, 2 so that their discussion in a 
treatise upon pathology might seem a work of supererogation ; the plan 
of the book, however, demands their brief mention. 

Malposed teeth may occupy any position relative to the dental arch y 
and any teeth of the dental series may be the offenders, although most 
commonly noted in connection with the incisors. So common is some 
degree of irregularity of the position of the lower incisors that its appear- 
ance is scarcely regarded as abnormal. The teeth may be inside or 
outside the dental arch, or have their transverse axes at any angle with 
the arch line — i. e., may be rotated in any manner. In the most ag- 
gravated cases an entire half denture may be malposed as regards its 
relations with the opposing or antagonizing half. Instead of having 
the upper teeth occluding outside the lower, they may occlude inside 
(Fig. 194). They may occlude squarely without incisor overlapping. 
Both of these abnormal conditions are, of course, due to lack of corre- 
spondence between the development of the lower and upper jaws. If 
one jaw has developed normally, the other has necessarily developed 
insufficiently or too much. 

1 American Text-book of Operative Dentistry. 

2 Guilford, Orthodontia ; Angle and others. 



228 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

Malpositions of entire groups of teeth are found attended by an 
insufficient development of the alveolar bone of that region. Thev 
may also be caused by an excessive development of some section of the 
alveolar bone. The underlying causes of these gross aberrations are 

Fig. 194. 




only imperfectly made out. The reasoning adopted in discussing their 
causes and the conclusions reached appear to be largely speculative, 
although some of them are plausible. (The reader is referred to mon- 
ographs upon orthodontia for the full discussion of these matters.) 



CAUSES OF MALPOSITIONS. 

The causes for the malpositions of individual teeth are frequently 
traceable with a reasonable degree of certainty. The upper lateral in- 
cisor has an inherent disposition to erupt inside the dental arch ; its 
crown during the formative stage lies slightly behind the crowns of the 
cuspid and central incisor ; again, the forms of the alveoli of the tem- 
porary teeth, if regarded as rounded triangles on section, have the bases 
of the triangles of cuspid and central incisor outward, while the base 
of the triangle of the lateral incisor is inward, hence a line inward to 
the arch is the direction the crown of the lateral incisor tends to follow. 
Erupting normally, this tooth has a disposition to cause outward dis- 
placement of the cuspid. The lower incisors, held in an arch by the 
nature of the occlusion of the upper teeth, and no doubt also by the 
tongue, have not the same freedom of alteration of position as have 
the upper teeth ; hence when the larger permanent teeth replace the 
smaller deciduous teeth they are crowded in the same arch-space and 
malposition results. It is evident that comparatively slight forces may 
deflect the direction of eruption of teeth, as they are only partially 
formed at the eruptive period, and are loosely enclosed. 

Effects of Extraction of Deciduous Teeth. — The effects of the 
extraction of the deciduous teeth largely depend upon the time at which 



MALPOSITIONS OF THE TEETH. 229 

the extraction is done. The general effect of extraction of the tempo- 
rary teeth before their permanent successors are ready or nearly ready 
to occupy their places is a lack of space for the accommodation of the 
permanent successor, causing a delay in its eruption. The extrac- 
tion of a temporary tooth interferes not only with those formative 
changes in the alveolar bone which afford increased space for the suc- 
ceeding permanent tooth, but interferes also with the resorptive process 
which frees the permanent tooth from the roof of its cavity. An 
additional feature is the usual narrowing of the space from which the 
tooth has been removed. These conditions are more clearly observable 
in the case of the too early extraction of the temporary second molars. 
Not infrequently these teeth are extracted prior to the seventh year, or 
even earlier. Four years or thereabouts must then elapse before the 
permanent successor makes its appearance. The crown of the latter 
lies in the base of the alveolar bone, covered upon all 
sides by bony walls, and its position is lower than FlG * 195 - 

the roots of the adjoining teeth, the temporary first 
and permanent first molar. The normal tendency 'A*&i^$I 
of the latter tooth is forward, and in the absence 
of the second molar it may attain a position imme- 
diately contiguous to the posterior surface of the 
first temporary molar. If the extraction occurs 
before the eruption of the permanent first molar, 
the condition described is almost certain to obtain, Effects of the premature 
hence when the period of eruption for the second secondmoiat"^ 0118 
bicuspid arrives, the tooth is compelled to take a 
direction inward or outward of the dental arch, or, as happens in some 
cases, the tooth does not erupt at all, but remains impacted or encysted. 
Similar effects may be noted in connection with the remaining anterior 
teeth. The injury caused by extraction has been said to interfere with 
the normal formative processes occurring in the follicle of the corre- 
sponding permanent tooth. Such an effect is not at all improbable. 
Effects of Delayed Loss of Deciduous Teeth. — If the resorption 
of the roots of the temporary teeth does not keep pace with the advance of 
the permanent teeth, more or less deflection of the course of the latter is 
almost certain to ensue. Recognizing the positions of the crowns of 
erupting anterior permanent teeth in relation with the roots of the ante- 
rior temporary teeth, it is evident that the general tendency of faulty 
eruption in these cases is inward. Comparatively and actually slight 
forces may deflect the course of an erupting tooth, hence the lower 
incisors, erupting before the upper, even though inward of the arch, 
are frequently driven into the arch -line by the muscular force of the 
tongue ; the upper incisors, erupting later and inward, are imprisoned 




230 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

by the lower incisors. It needs but the contact of slight occlusion to 
transform a slight into a marked malposition. 

A curious relationship is sometimes established through the long 
retention of a temporary molar : the alveolar process develops normally 
and carries with it bodily the retained temporary tooth to a higher level, 
to the same level occupied by adjoining teeth, so that the tooth is in 
correct occlusion, although raised far beyond its original level. The 
eruptive impulse of the permanent successor of such retained temporary 
teeth seems to exhaust itself without avail, and the temporary tooth 
remains as a permanent feature of the adult denture. 

Treatment. — When it is evident that the presence of a temporary 
tooth has deflected the line of eruption of its permanent successor it 
should be removed. When temporary teeth are retained beyond the 
normal period of eruption of their successors some operators advise that 
they should be extracted, a procedure said by them to hasten the appear- 
ance of the permanent successors. This rule is too sweeping, for erup- 
tion may be delayed from a variety of but partially understood causes, 
and the violence of extraction may disturb instead of aid eruption. 
However, when there is a pulpless temporary tooth in the arch, and all 
of the corresponding permanent teeth are in position, the indication is to 
extract the pulpless tooth. The process of resorption is faulty and in- 
complete in such cases, and it is probable that the extraction of the tooth 
removes a mechanical obstruction to the eruption of its successor. In 
the absence of an appearance of the crown of a permanent tooth, and 
with no evidences of loosening of the healthy temporary tooth, the 
forcible extraction of the latter is rarely advisable. It has happened 
that firm and sightly temporary teeth have been extracted, but no per- 
manent successor appeared. 

Effects of the Early Extraction of the Perma- 
nent First Molar. — The permanent first molar erupted 
from the sixth to the eighth year may suffer from dental 
caries, pulp-necrosis, or alveolar abscess before the tenth 
or eleventh year. If these teeth are extracted, a char- 
acteristic dental deformity follows. Kecalling that the 
development of the jaw proceeds in such manner that 
the depth of the alveolar bone is constantly increasing 
until adult age, and that this development is only 
marked during and after the appearance of the second 
E Tufe S ios f sofTer- dentition, it is evident that the extraction of the per- 
manent first mo- manent first molar is followed by a lessening or cessation 
of development of the bone adjacent ; the formative pro- 
cess will not then deepen the lateral alveolar walls until the period of 
eruption of the bicuspids, not for three years or more. In the mean- 




MALPOSITIONS OF THE TEETH. 231 

time the permanent incisors erupt and the alveolar bone deepens 
around them ; their occlusion is not limited in extent by a corre- 
sponding deepening of the posterior alveolar bone. The lower in- 
cisors, being without check to their action, come to strike the upper 
incisors at their cervico-palatine portions ; these latter teeth are gradu- 
ally driven from their vertical positions until they assume almost a hori- 
zontal direction. 

Treatment. — The treatment of this condition is preventative : the 
permanent first molars should not be extracted until the bicuspids 
have fully erupted, provided that their retention is possible. The perma- 
nent first molars, far from being, as was once held, the most worthless 
teeth of the dental series, are the most important. Their eruption at an 
early period is a distinct indication of the important influence their pres- 
ence exerts upon the normal development of the alveolar bone about and 
posterior to them. Their eruption is about synchronous with the com- 
pletion of the evolution of the alimentary canal and its appendages ; 
hence their office in the increased mastication, normal at this time, is 
clear ; their presence beyond a doubt determines the extent of the for- 
mative process which shall occur in the alveolar bone posterior to them. 
From the period of their eruption they should be carefully scrutinized ; 
and even though caries and subsequent disease-processes act to the ex- 
tent of alveolar abscess, the conditions are to be vigorously treated, so 
that the teeth may be retained until after the eruption of the second 
bi uspids. 

IMPACTED AND ENCYSTED TEETH. 

The extreme extent of dental malposition is reached when the perma- 
nent teeth do not erupt at all. Instead of presenting in the dental arch, 
they may be entirely imbedded in the substance of the bone, either re- 
maining there, with or without pathological manifestations, or erupting 
in some very unusual situation. In other cases a distinct cystic tumor 
forms about the enclosed tooth. 

Impacted Lower Third Molars. — By far the most common dental 
impaction is that of the lower third molar. The extent of impaction 
varies from a partial eruption, or partial imprisonment of the tooth by 
its bony surroundings, to its entire imprisonment in any part of the 
maxilla. Many of the more severe cases treated of under the head of 
difficult eruption, if unrelieved would be included in the category of 
impacted teeth. 

In Fig. 197 is shown a lower third molar presenting the effects of a 
previous impaction. The irritation caused by the efforts of the tooth to 
disengage itself or to overcome the resistance to its eruption has caused 
an active formative reaction in the pericementum, resulting in a hyper- 
trophy of the cement um. 



232 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

If the distance between the posterior surface of the second molar 
and the columns of the coronoid process be very short, it is evident that 
upward eruption is impossible, so that the tooth may assume any direc- 
tion of movement, the most common being forward, the axis of the tooth 



Fig. 197. 




Right half of lower jaw, showing an impacted third molar. (Cryer. 

Fig. 198. 




Inner side of left half of same lower jaw. (Cryer.) 

changing its position until the tooth may lie in a horizontal position or 
even become inverted. 

Fig. 198 is taken from the same jaw as Fig. 197, but shows the 
opposite side ; the impaction is pronounced. Fig. 199 shows another 



MALPOSITIONS OF THE TEETH. 



233 



case with different anatomical surroundings. In the first case there were 
evidences both in the tooth, in its bony surroundings, and in the exter- 
nal cortical bone, of the results of the irritation produced by the efforts 
at eruption. The cementum was thickened ; the outer follicular wall, 



Fig. 199. 




(Cryer 



the tissue designed to form the alveolar periosteum, had exercised its 
formative osteogenetic function, and a capsule of bone had formed about 
the tooth ; it lay in a bony chamber. The pressure exerted upon the 
distal wall of the second molar had resulted in a pressure-resorption of 
its root until the pulp-chamber was encroached upon. In Fig. 199 the 



234 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

root-development has caused impingement of the root-apex upon the 
inferior dental canal. These were both post-mortem cases, and no 
records of their clinical histories were obtainable. The symptoms 
produced could only be surmised by the nature of the anatomical rela- 
tions and the pathological evidences. There may have been a prolonged 
but mild periostitis, probably a continued pulp-irritation ; and in the 
last, neuralgia of any grade of severity. 

Fig. 201. 




Wisdom-teeth imbedded in the rami of the lower jaw. (Tomes.) 

Judging from post-mortem records, cases of impacted third molars 
are more common than generally believed. Instead of remaining in 

Fia. 202. 




Wisdom-tooth buried in the ramus. (Tomes, after Marshall.) 



the alveolar portion of the bone, the impacted tooth may come to oc- 
cupy a cavity in some portion of the body or the ramus of the bone 
(Figs. 201 and 202). The positions of the teeth in such cases tend to 



MALPOSITIONS OF THE TEETH. 



235 



confirm Tomes' theory of the development of the jaw. The jaw being 
lengthened, and the ramus developing through conjoined deposition and 
resorption of bone, the crown of the tooth appears to be either fixed in 
a bony nucleus and transported to some distant point in the develop- 
mental progress of the jaw, or to be irregularly shifted about during 
jaw-growth. At later periods the pressure exercised by root-formation 
disturbs the relations of the tooth with its earlier surroundings. These 
efforts at eruption may at late periods cause the appearance of the 
tooth in odd situations (Fig. 203). The crown of the tooth in this 

Fig. 203. 




From a wax model in the museum of the London Odontological Society. (Tomes.) 

case made its way through the angle of the bone and through the 
muscles and skin. The opening in the skin healed upon extraction 
of the tooth. 

Impacted Upper Third Molars. — Some grades of impaction of this 
tooth have been spoken of under the head of difficult dentition. The 

Fig. 204. 




Upper jaw, with the third molar directed forward, and impinging upon the second molar. The 
small tooth situated high up in the anterior part of the jaw, was forced there by the spade of 
the grave-digger. The artist's accuracy in delineating all parts of the specimen has rendered 
this explanation necessary. (Tomes.) 



most common is imprisonment of the tooth and its subsequent partial 
eruption in a horizontal position, the crown pointing toward the cheek 
(Fig. 204). The crown of this tooth may in rare cases be directed 



236 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 



Fig. 205. 




inward or backward, in the latter case being arrested by the pterygoid 
plates of the sphenoid bone. 

In a case recorded by Tomes (Fig. 205) the extraction of the second 
molar revealed the third molar in a reversed posi- 
tion, its roots occupying the depression between the 
roots of the second molar. 

Impacted Cuspids. — In point of frequency of 
impaction the upper cuspids stand next to the lower 
third molars. It will be recalled that the upper 
cuspids lie high up ; the floors of their crypts, in 
which they lie loosely, are at a higher level than 
those of the adjoining teeth ; they erupt at a much 
later period, and their crowns, as with the other 
anterior teeth, lie inside the roots of their predeces- 
sors. All of these are elements which might cause 
displacement of the developing cuspids. Should the advance of erup- 
tion not keep pace with the development of the alveolar bone, impris- 
onment is likely ; again, the dense bone immediately about the first 
bicuspid and lateral incisor may offer a deflecting resistance. Exam- 
ining the texture of the bone about these parts, it is evident that 
the least resistance to the advance of a much-deflected crown is into 
the cancellated bone of the incisor portion of the alveolar process ; 



A second molar of the 
upper jaw, with the 
wisdom-tooth invert- 
ed and embraced with- 
in the roots. (Tomes.) 



Fig. 206. 




Abnormal jaw, showing impacted cuspids. (Cryer.) 



hence it is most usual to find the crowns of these teeth lying with their 
cusp-point forward (Fig. 206). Several recorded cases have the posi- 
tions shown ; one or both of the teeth may be encysted. 

Impaction of Other Teeth. — While impactions are most common 



MALPOSITIONS OF THE TEETH. 



237 



in connection with the teeth named, any other teeth of a denture 
may be imprisoned. Fig. 207 shows an imprisoned bicuspid whose 
root-development has been normal as regards its length, but whose 



Fig. 207. 




Impacted bicuspid. (Salter.) 



curve has been modified by the resistance of surrounding tissues. Figs. 
208 and 209 exhibit an impacted central incisor, whose retention was, 



Fig. 209. 




/ 






^> 



~sr 




Imprisoned central incisor. (Kirk and Cryer.) 

no doubt, determined and malposition caused by the development 
and presence of the brood of supernumerary teeth which surround its 
crown. 



238 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

Symptoms. — The most common symptom attendant upon impaction 
of teeth, judging from the obtainable records of cases, is trifacial neur- 
algia of any degree, caused by impingement of the malposed tooth 

Fig. 210. 




Lower maxilla, in which the right second bicuspid is placed obliquely, the root being directed 
backward. The crown, though exposed, does not rise above the level of the alveolar margin. 
(Tomes.) 

Fig. 211. 




Maxilla, in which the temporary cuspids (the sockets of which are shown by the dotted lines) were 
retained, and the permanent canines developed within the substance of the jaw. The bone 
has been removed on the one side to show the direction taken by the tooth, which has been 
twisted on its axis to the extent of a quarter of a turn. (Tomes.) 



Fig. 212. 



upon nerve-filaments or trunks. Cryer l records a case where a supra- 
maxillary neuralgia was traced to the presence of a central and lateral 

incisor, and a cuspid tooth in the anterior Avail 
of the antrum ; they were only discovered by 
an exploratory operation (Fig. 212). A cure 
of the neuralgia was effected by their removal. 
Impacted third molars frequently give rise 
to heavy rheumatic pains about the side of the 
face and jaws, and no doubt in such cases as de- 
picted in Fig. 199 would cause intractable and diffuse maxillary neur- 
algia. Salter 2 records a case of long-standing and intractable neuralgia, 
1 Dental Cosmos, 1896. 2 Dental Pathology. 




MALPOSITIONS OF THE TEETH. 239 

exhibiting a constant painful area upon the scalp, and in which heat and 
tenderness were noticed over a swelling upon the hard palate. Imme- 
diate and permanent cessation of the neuralgia followed removal of 
the teeth. 

Symptoms of maxillary periostitis — heavy, gnawing, and dull, 
throbbing pain, with more or less heat and engorgement of tissues — 
are noted as an accompaniment of impacted teeth. Such symptoms 
may herald the appearance of the tip of the tooth through its bony 
covering and gum. 

Cases of maxillary abscess, in the absence of their usual (dental) 
cause, may run a prolonged and painful course, 1 involving neighboring 
structures, and after free venting be found to have arisen about an 
impacted tooth. 

Occasionally a circumscribed swelling is noted upon some aspect of 
a jaw, most frequently upon the palatal portion of the superior maxilla, 
which is attended by inflammatory symptoms, and an incision reveals 
an impacted tooth. 

Quickly forming cysts of the jaw upon receiving surgical treatment 
may be found to contain the crown of an entire tooth, this evidently 
being the centre of irritation from which the cystic formation had its 
origin. 

Diagnosis. — The first point of observance in cases of suspected 
tooth-encystment is an examination of the dental arches. Are all of 
the permanent teeth in position? Given the absence of, particularly, 
a lower third molar from the dental arch, with a history of no eruption, 
and a persistent neuralgia, particularly if occasionally accompanied or 
alternated by heavy rheumatic, what are known as bone-pains, and find- 
ing no other evident cause of the neuralgia, the effects of an impacted 
tooth would be naturally diagnosed as the source of the disturbance. 
Impacted teeth which lie horizontally or nearly so along the palatal 
vault frequently cause a swelling. This, taken in conjunction with the 
absence of a tooth from the dental arch, points to a diagnosis of im- 
paction. 

In very many cases of impaction diagnosis has been a mere accident, 
discovery being made in the course of an exploratory surgical operation. 
Modern science solves with the x-ray the difficulties attendant upon the 
diagnosis of impacted teeth. B. H. Catching 2 was the first to prac- 
tically apply this diagnostic test for the location of an impacted tooth. 
The left upper central incisor of a female aged nineteen became loos- 
ened, and an exploration through its pulp-chamber revealed a hard 
body occupying a position part way up the root, which had undergone 

1 See Garretson's Oral Surgery, and Salter's Dental Pathology. 

2 Catching' s Compend, 1896. 



Fig. 213. 



240 MALFORMATIONS AND MALPOSITIONS OF THE TEETH. 

resorption to that point. The cuspid of the left side was absent from 

the arch. A skiagraph of the parts (Fig. 213) revealed the missing 

cuspid, whose crown had impinged upon and 
caused resorption of the root of the central 
incisor. 

Impacted teeth may become uncovered at 
some aspect late in life and the condition be 
discovered incidentally. Cases are recorded 
where the pressure of a plate has caused the 
resorption of tissues overlying an impacted tooth, 
thus revealing its presence. Fig. 214 illustrates 
a case where the presence of an impacted cuspid 
was revealed at the age of seventy years, through 
resorption of the alveolar bone and the gum- 
tissue covering the tooth. 
Beyond a doubt, the a>ray will be generally used in the future to 

determine the position of permanent teeth absent from the dental arch ; 

and will be used as a means of diagnosis when the presence of impacted 

teeth or an odontoma may be suspected. 

Fig. 214. 



X-ray photograph, showing 
the malposed cuspid en- 
tirely embedded in the 
bone, and pointing on the 
central. 




Treatment. — The treatment of cases of impaction is the removal 
of the offending tooth. Whether or not this comes within the prov- 
ince of the dental operator depends upon the position of the tooth, 
and, incidentally, upon the usual range of practice of that par- 
ticular practitioner. When the tooth is imbedded deep in the sub- 
stance of the jaw, access to it involves the etherization of the patient 
and the removal of the bone which obstructs the path of extrac- 
tion ; this may be an operation of some magnitude, and is usually done 
by a special surgical practitioner. When, however, it is evident that the 
obstructions to the removal of the tooth consist of the soft tissues and 
but a lamina of bone, the operation for removal is clearly Avithin the 



MALPOSITIONS OF THE TEETH. 241 

province of the dental operator. For example, the presence of an 
impacted cuspid is determined lying horizontally along the lateral 
aspect of the roof of the mouth. The parts may be injected with a 
cocain or eucain solution, and a curved cut made with a sharp bistoury 
through the soft tissues at the dental side of the swelling to the bone. 
The flap thus outlined is raised from the bone, the flap including the 
periosteum. A large sharp bur is then employed to remove the covering 
bone. When the tooth is freely exposed it may be dislodged with 
forceps or elevator. The parts are then washed with a hydrogen dioxid 
solution, dried, the flap pressed back into place, and steresol (which see) 
painted over the parts. 

The treatment of such cases as Fig. 207 is the same. 

16 



SECTION III. 

AFFECTIONS OF ENAMEL AND DENTIN. 



CHAPTER XL 
AFFECTIONS OF THE ENAMEL. 

It has been repeatedly stated in the preceding pages that enamel 
plays an entirely passive part in disease-processes. Being cut off at the 
completion of its formation from all sources of nutrition, it is deprived 
of all defensive mechanism against agencies which may threaten its 
destruction. Furthermore, recognizing this absence of nutritive mech- 
anism, it is evident that enamel cannot be subject to the classes of dis- 
eases which affect vital tissues ; that is, degenerations and the causes 
of degenerations have no representatives in affections of the enamel. 
While the enamel may suffer loss of substance, it is not possible that 
constructive or retrogressive metamorphosis can take place. 

The enamel can be regarded only as an inert chemical substance, the 
exact chemical morphology and composition of which are but imper- 
fectly understood. It is acted upon by a variety of physical forces and 
chemical agencies which threaten the destruction of its substance, either 
through mechanical injury or chemical solution, and against which 
agencies it is incapable of any but mechanical and an unalterable 
chemical resistance. The disease-causes operating against the integ- 
rity of the enamel of the teeth are mechanical and chemical; both 
of these cause a loss of substance, but in a different manner ; again, 
they may act together. The mechanical forces act as destructive agents, 
either by removing the enamel particle by particle by a process of 
abrasion, or by causing fracture, complete or incomplete, of masses of 
enamel. It appears in some cases that, in addition to direct mechanical 
violence, abnormal temperatures to which the enamel may be subjected 
cause linear fractures of enamel-plates. Enamel suffers from chemical 
solution both through the action of acids formed in the mouth during 
fermentative processes, and probably, by morbid acid secretions of 
glands, also through the action of acids present in food or taken 
as medicinal agents. 

243 



244 AFFECTIONS OF THE ENAMEL. 

Mechanical Injury op Enamel. 

It was pointed out in Chapter VIII. that the resistance of enamel 
against crushing-forces is comparatively slight, and that its resistance 
in this direction is much modified according or not as the tissue is uni- 
formly and firmly supported by dentin. Masses of enamel, therefore, 
which are deprived of the normal support of underlying dentin are in 
danger of fracture. It is frequently noted that teeth which give no 
very apparent external indication of loss of dentin, the enamel contour 
being almost intact, may exhibit an extensive disorganization of the 
dentin, through a comparatively light stress causing fracture of the 
enamel. Biting upon a crust may be followed by crushing of the 
greater portion of the enamel-cap, revealing, as the underlying cause 
of the fracture, disappearance of dentin support. 

The enamel of teeth appears to differ in fragility, both as regards 
individuals and the several teeth of one denture. 

Fracture of enamel en masse occurs more readily with pulpless teeth, 
those in which decomposition of the contents of the dentinal tubuli has 
taken place, than it does with teeth containing vital pulps. Its resist- 
ance is much greater in teeth in which the tooth-pulp has been devital- 
ized and removed and the canals filled under aseptic precautions, with 
absolute exclusion of saliva, than when the saliva has been permitted 
free entry into the interiors of the teeth. 

Through either lack of perfect adaptation or improper character of 
support, enamel-walls underlaid by gold or amalgam fillings are much 
more liable to fracture than if supported by zinc-phosphate cement. 
It should be remarked in this connection that the chief and most 
valuable use of zinc phosphate in dental practice is as a mechanical 
substitute for lost dentin. 

The accepted rule of operative dentistry, not to pack gold against 
unsupported enamel-walls, is a well-founded one. The danger of frac- 
ture is twofold : first, fracture during the operation of impaction ; sec- 
ondly, subsequent fracture due to improper support. 

Enamel (see Chapter VIII.) has lines of least mechanical resistance, 
which are in planes at right angles to the general direction of the en- 
amel-rods ; that is, enamel fractures most readily along the lines of the 
cementing-substance of the enamel. In addition to these uniform lines 
of low resistance there appear to be others which invite fracture along 
straight lines passing from the occlusal edges of the enamel to its cervi- 
cal border ; longitudinal fracture of the entire length of an enamel plate 
occurs. These lines may be observed in the enamel of persons who 
habitually break ice and other hard substances with their teeth. Iden- 
tical lines of fracture are found in enamel which patients deny having 



MECHANICAL INJURY OF ENAMEL. 245 

subjected to such usage ; they have been attributed to the contact of 

excessively hot or excessively cold substances with the enamel, a 
reasonable hypothesis. 



ABKASION OF THE ENAMEL. 

By abrasion of the enamel is meant a wearing away of its substance 
through the friction of mastication when gritty substances are present. 
Some forms of abrasion have been attributed to the too vigorous use 
of hard tooth-brushes, particularly when gritty tooth-powders are em- 
ployed. There is no doubt that mechanical abrasion about the necks 
of teeth is produced in this manner, the gum-line receding beyond the 
enamel-border, exposing the cementum : but a careful examination will 
reveal the cementum, and next the underlying dentin to be affected ; the 
enamel is not abraded. These tooth-brush abrasions are quite charac- 
teristic (Fig. 215). In well-kept dentures the gums are seen to have 
receded from their normal line, but exhibit no evidences of turgescence ; 
the roots of the teeth, upper and lower, are exposed to a greater or less 
extent along their labial and buccal, but not along their lingual aspects ; 
and they are excavated to variable depths, upon 
the bicuspids and first molars more than upon the Fig. 215. 

other teeth, as here the greatest force of brushing 
is received. The depressions have a normal den- 
tin color, which in smokers may be periodically 
blackened by deposits of carbon. If caries super- 
venes, the abraded areas lose their normal color, 
and may be readily indented by sharp instruments, 
which they resist before the advent of caries. The 

bicuspids and molars particularly may be grooved in such manner as to 
require restoration by fillings. 

Abrasion of enamel-surfaces through the constant rubbing of 
metallic clasps of prosthetic appliances has been said to occur, but it 
is impossible to disassociate in this connection the effects 
of the acids of fermentation. Food-debris on the inner 
surface of a clasp undergoes fermentative changes, and 
acids are formed which act as decalcifying agents upon 
the enamel ; so that the abrasion of the clasp is not 
upon normal enamel-surfaces, but upon partially decal- 
cified enamel. This fact becomes more evident when it 
is observed that the abraded surfaces are not smooth and polished, but 
are roughened. There is no doubt that the continued rubbing of a 
clasp upon a tooth will abrade enamel slightly, but the surface produced 
is polished. The abrading effect of clasps in contact with cementum or 





246 AFFECTIONS OF THE ENAMEL. 

dentin is unquestionable, but there is also in such cases the conjoined 
effect of acids of fermentation. 

By far the most common cause of the abrasions noted upon the 
occlusal surfaces of teeth is tobacco-chewing. The silex contained in 
tobacco-leaf acts as an irresistible abrading agent. The cases in which 
this form of abrasion is most marked are those in which there has been 
originally but little overbite of the upper teeth, or in which the teeth 
have a tip-to-tip occlusion. There appears to be a tendency with this 
type of occlusion for the occlusal surfaces of the teeth to abrade. There 
are always a free lateral movement of the mandible, and a type of sur- 
face-contact resembling that of the herbivora. Whether due to the 
type of occlusion itself or that with this type of occlusion the individual 
more frequently chews the siliceous stems of vegetables, it is with such 
patients that general abrasion is most common. It is also frequent 
in those cases presenting the first degree of prognathism. In all of 
these cases, after the abrasion has worn down the teeth to the cusp- 
bases, the occlusion tends to become of the tip-to-tip variety. When 
there is a more marked overbite occlusion, with a consequent lessening 
of lateral movement of the mandible, the teeth do not acquire flattened 
contact-surfaces, but their cusps increase in sharpness and pointedness. 

The effects of abrasion are to leave sharp enamel-edges standing, 
which when the dentin becomes exposed grow more sharp and more 
pointed. Being Avithout direct dentin support and receiving stress in 
abnormal directions, the enamel tends to fracture. 

In the overbite cases the conjoined action of abrasion and of gradual 
molecular fracture of enamel creates curiosities of occlusion. The 
teeth of the upper and lower jaws may interlock their cusps in such a 
manner that the line of junction is almost invisible. 

The sharp enamel-edges produced not only increase the liability to 
enamel-fracture, but act as constant sources of irritation to soft tissues 
which come in contact with them, the most frequent result being 
abrasions upon the side of the tongue, producing ulcers of a sometimes 
chronic type which acquire indurated edges and simulate syphilitic sores 
or epithelioma. The causal relationship between sharp edges of the 
teeth and lingual epithelioma appears to be quite clear in some cases. 1 

Sores which have given evidence of malignancy and been diagnosed 
as malignant growths have been cured by rounding and polishing sharp 
and irritating enamel-edges of teeth. 

Treatment of Abrasion. — If seen early enough, the treatment of 
abrasion should be preventative. Abrasion has unquestionably been 
arrested by cessation of the tobacco-chewing habit. A difficult class 
of cases to treat is found in those highly nervous individuals who 

1 Garretson's Oral Surgery. 



EROSIONS OF THE TEETH. 247 

grit their teeth during sleep. It is probable and reasonable that this 
cause alone may serve to explain abrasions traceable to no other 
source. The cure of such cases as these could only be possible 
through the wearing at night of some modified form of interdental 
splint. The cases naturally indicate the medicinal use of a bromid 
before retiring. 

It is rare that any remedial measures are adopted or, indeed, even 
advisable, unless the abrasion wears the teeth down far below the cusp- 
line, although the dentin exposed through the loss of enamel may become 
hypersensitive and require treatment. The mildest agent affording 
relief is carbolic acid. For the relief of periodical hypersensitivity 
the use of a mouth-wash of dilute phenol sodique is effective if con- 
tinued. Some spots of hypersensitiveness resist every measure ex- 
cept applications of strong mineral acid. The action of these acids, 
sulfuric, nitric, or hydrochloric, being chemically destructive, the spots 
of application must be subsequently excavated and filled. 

The radical relief of the condition is by the operation called " shoeing " 
the teeth. Each abraded tooth is to have built upon it sufficient gold- 
foil to receive the stress of mastication. The fillings must be of such 
thickness that the stress of mastication cannot alter their forms, and 
be built as solidly as molten gold ; to assure this they are made of 
heavy rolled foil, No. 30, No. 60, and for the final surfaces No. 120. 
In many cases it is advisable to use for this purpose platinum-gold foil, 
which resists attrition better than gold-foil itself. 

Cases of attrition of the oral teeth and of the bicuspids are fre- 
quently seen where the loss of several molar teeth has permitted the 
entire stress of mastication to come upon the anterior teeth. These 
cases are treated by adjusting bridge fixtures in appropriate spaces, 
whose occlusion shall raise the bite — i. e., separate the jaws to the 
proper extent ; hard-foil fillings are then inserted in the worn anterior 
teeth, restoring to them their original forms. 

In case the abrasion is very deep upon all of the teeth, it is advisable 
to fit gold crowns of the barrel variety upon the posterior teeth and 
adjust porcelain-faced crowns over the anterior teeth. The pulps of 
the teeth need not necessarily be destroyed. 1 

Erosions of the Teeth. 

Erosion of the teeth is a term applied to the decalcification of the 
hard tissues of teeth in such a manner that broad, shallow excavations 
are made in the enamel, and in such situations that the acids of fermen- 
tation and mechanical abrasion are clearly excluded as exciting causes. 
The excavations occur upon surfaces where fermentative processes are 
1 See American Text-book of Prosthetic Dentistry, chapter xxii. 



248 



AFFECTIONS OF THE ENAMEL. 



in least degree and where attrition is nil. Figs. 217, 218, and 219 
illustrate the characteristic appearance of areas of erosion. 

The labial faces of the anterior teeth are more frequently affected than 
those of any of the other teeth. These surfaces appear as though sections 



Fig. 217. 




Fig. 218. 




(Darby. ) 



(Darby.) 



had been bodily cut out of them. The enamel is affected to a greater 
extent than the dentin, forming shallow excavations in the teeth. When 



Fig. 219. 





A case of erosion (drawn from the cast) : B, silhoutte from a perpendicular line through the left 
centrals, upper and lower, showing the loss of substance. (Black.) 

the destructive action lays bare the dentin, neither it nor the enamel 
presents any of the appearances of dental caries, the eroded surfaces 
being smooth and polished and of normal hardness. 



r 



CAUSES. 

From the chemical composition of the enamel it is at once evident 
that the essential cause of the loss of structure must be an acid ; 
only acid substances can dissolve it. The question of mechanical 
abrasion may be set aside because erosion has been found upon the teeth 
of individuals who had never used a tooth-brush, and the situation of the 
areas precluded the idea of abrasion by mastication. It is evident that 
the acid must be of localized formation, because if of general distri- 
bution the lingual and occlusal faces of the teeth would be affected 



EROSIONS OF THE TEETH. 249 

equally with the labial. It will be observed that the areas of erosion 
are in situations in which food-debris, fermentable material, collects in 
least amount, and where the acids of fermentation necessarily form in 
slight amount. This survey materially narrows the field of inquiry. 
What structures or substances can form acids or acid bodies about the 
labial faces of the teeth, excluding fermentative processes? The 
inquirer is of necessity driven to the belief that local acid secretion is 
the active cause. Secretion implies the existence of glandular tissue, 
and the only glands in close relationship with the labial faces of the 
teeth are the muciparous glands of the lips ; mucus-forming glands, 
called labial follicles. Edward C. Kirk l first pointed out the prob- 
ability of altered (acid) secretion of these glands being the active cause 
in the production of erosion. 

It has been recorded by those who have made a special study of the 
condition that females are more frequently affected than males ; that it 
rarely becomes evident before the age of thirty or later ; and, finally, 
that patients in whom it is noted are usually the victims of the condition 
indefinitely known as the gouty diathesis. The observations of Kirk, 
Darby, Jack, and myself have all had a singular unanimity of agree- 
ment in this direction. Most of the patients give a family history of 
gout, and very commonly a personal or contemporary family history of 
rheumatoid arthritis or rheumatism. Even when the existence of rheu- 
matoid or gouty affections is denied by both patient and medical attend- 
ant, it is rare that the patient does not complain of some general disorder, 
the usual ones being neuralgia of long standing, marked anaemia, or 
perhaps neurasthenia. Be the condition what it may, the essential 
disease-process is one which may be traced to the effects of suboxidation 
in the tissues. 

The researches of general pathologists as to the products of cell- 
oxidation but insufficiently explain the origin and significance, both 
chemical and pathological, of a series of bodies related to urea, un- 
questionably waste-products resulting from broken-down, oxidized albu- 
minous matter. These related products are uric acid, xanthin, and hypo- 
xanthin, which represent, chemically at least, degrees of albuminous 
oxidation — urea the most oxidized, hypoxanthin the least. While the 
writer is aware 2 that pathological chemists refuse to recognize uric acid 
as a midway product in urea-formation, yet it cannot be denied that 
uric acid will form in increased amount if the oxidizing function be 
below par ; all clinical and scientific reasoning appears to point to this 
end. Note the conditions in which an increase of uric-acid formation is 

1 Dental Cosmos, 1886. 

2 See Levison on Uric Acid; Luff, Croonian Lectures, 1897; Halliburton, Chan. 
Physiol, and Pathology. 



250 AFFECTIONS OF THE ENAMEL. 

observed. It should be remarked parenthetically that uric acid cannot 
exist free as uric acid in the blood, but when formed combines imme- 
diately with sodium or magnesium, doubtless displacing the negative 
radical of compounds, and forming sodium or magnesium quad-urates. 

An excess of urates is formed whenever there is an excess of white 
blood-corpuscles, in conditions of anaemia, leukaemia, and so on. The 
significance of these conditions lies more in the deficiency of red cor- 
puscles than in the excess of white. Less red corpuscles, less haemo- 
globin, less oxygen carried, hence diminished oxidation in the cells. 
Again, in the opposite, the plethoric individual, who suffers from acute 
outbreaks of gout, large quantities of albuminous food are taken, 
amounts far in excess of that required to replace waste ; frequently, 
owing to glandular disturbances of the alimentary canal, the material is 
insufficiently elaborated, and the tissues of the body are drenched with an 
excess of material in unfit chemical state for cell-metabolism ; the 
amount of oxygen, actually large, relatively small, is insufficient to 
oxidize all of the material of which the cells of the body should rid 
themselves. Conjoined with this, the same individuals usually consume 
too much alcohol in one form or another, and alcohol notably lessens 
cell-oxidation. 

The relation between an excessive formation of urates and deficient 
oxidation may in a like manner be made out in many of the other con- 
ditions. A deficiency of oxidation or in the supply of oxygen is, of 
coarse, accompanied by retention of C0 2 in cells, so that all of the 
waste-products of cells are but imperfectly removed. It should also be 
noted that the products of cell- waste are acid in reaction. 

" If the orbicularis oris muscles be dissected from the mucous mem- 
brane of the lip, the labial glands may be observed ; they are more 
numerous near the centre than at the extremities of the lip" l — i. e., the 
greater number overlie the labial faces of the incisors toward the 
necks of these teeth. " These are small racemose glands, their ducts 
lined with low granular epithelium ; in the alveoli the cells are larger 
and columnar and stain less readily with carmine." " Their secretion is 
composed of water, mucin, and inorganic salts, sodium phosphate pre- 
dominating, which gives the fluid its alkalinity under normal condi- 
tions. In conditions of irritation and consequent hyperaemia the 
secretion becomes increased in amount and acid in reaction (Kirk). The 
nature of the acid is not clearly known. Brubaker 2 suggested that it 
might arise as follows : 

In the condition known as the gouty diathesis there are evidences 
of widespread irritation ; the presence of an excess of waste-products 
appears to be the cause of the irritation. In consequence of the irrita- 

1 Brubaker, International Dental Journal, Dec., 1894. 2 Ibid. 



EROSIONS OF THE TEETH. 251 

tion there is a vascular reaction about glands, as those under con- 
sideration, which results in increased secretion, and as the oxidizing 
function is imperfect the C0 2 accumulates. "Given upon one side, 
the vascular side, of the cells the readily diffusible and alkaline salt 
sodium phosphate, Na 2 HP0 4 , and in the cell an excess of C0 2 , existing 
as H 2 C0 3 , or carbonic acid, when the sodium salt diffuses into the cell 
the following reaction occurs : 

Na 2 HP0 4 + H 2 CO s = NaH 2 P0 4 -f NaHCO s . 1 

That is, dihydrogen sodium phosphate (acid sodium phosphate) and 
acid sodium carbonate are formed. Dihydrogen sodium phosphate, 
being acid in reaction, is capable of effecting the decomposition of 
the calcium phosphate of the teeth after the following manner : 

NaH 2 P0 4 + Ca 3 (P0 4 ) 2 = NaCaPO, + 2HCaP0 4 . 

" The acid sodium phosphate formed in the gland-cells and given off 
by them attacks the calcium salts of the enamel, as above expressed, a 
double decomposition occurring, sodium calcium phosphate and acid 
calcium phosphate being formed. The latter, acted upon by additional 
molecules of the dihydrogen sodium phosphate, 

NaH 2 P0 4 + 2CaHP0 4 — NaCaP0 4 + Ca(H 2 P0 4 ) 2 

and the freely soluble diacid calcic phosphate is formed. In this way 
the calcium phosphate of the teeth undergoes decomposition into, first, 
mono, and, second, the diacid calcic phosphate." Brubaker immersed 
a tooth for a week in a solution of acid sodium phosphate, subjecting 
it daily to tooth-brush friction, and at the end of that time spots and 
grooves resembling areas of erosion made their appearance. 

While admitting the probability that dihydrogen sodium phosphate 
is the decalcifying agent, Kirk maintains 2 that the reaction between 
the hypothetical substance, carbonic acid, H 2 C0 3 , and sodium phosphate 
is a chemical impossibility, as the reaction given involves the production 
of acid sodium carbonate in the presence of acid sodium phosphate, 
which cannot occur. 

He suggests that the probable origin of the acid sodium salt is from 
the reaction occurring between hydrogen disodium phosphate, Na 2 HP0 4 , 
and uric acid, C 5 H 4 N 4 3 , citing from Hammersten that uric acid, soluble 
in a warm solution of hydrogen disodium phosphate, fflSa 2 P0 4 , in an 

1 It is to be understood that Brnbaker advances this explanation hypothetically, not 
as an assured demonstration, as he says there are no present tests by which such small 
amounts of the acid substance can be detected. 

2 Private communication. 



252 AFFECTIONS OF THE ENAMEL. 

excess of the acid, a double decomposition or atomic interchange occurs 
as follows : 

HNa 2 P0 4 + C 5 H 4 N 4 3 = H 2 NaP0 4 + C 5 H 3 N 4 3 Na, 

resulting in the formation of sodium biurate and the acid sodium phos- 
phate, H 2 NaP0 4 , which may act as a decalcifying agent after the manner 
described by Brubaker. 

The uric acid involved in the reaction is to be regarded as a conse- 
quence of faulty oxidation in the glandular tissues. The sodium biurate 
found in the reaction given above may act as an irritant and induce a 
continuation of the glandular affection. 

Kirk has pointed out that the contents of the labial glands in cases 
of erosion gave an acid reaction — i. e., reddened blue litmus paper — in 
all of the cases tested by him. 

It appears to be almost self-evident that there must be some modifying 
factor causing the peculiar forms of the eroded areas, and that 
it must be an abrasive. In many of the cases where the ero- 
sions are in the form of transverse grooves or pits there is no 
doubt that the action of the tooth-brush upon the decalcified parts 
removes the latter ; the areas of erosion may be oval, circular, 
or irregular patches ; again, decalcification may appear to occur 
over the entire labial surfaces of teeth uniformly ; moreover, as 
stated, erosions in grooves may occur upon the teeth of persons who 
do not use a tooth-brush. It is evident then that in these cases the 
mechanical factor must be sought in the muscular movements of the 
lips and tongue. The greatest effect of lip-movement would be upon 
the entire labial faces of the central incisors, as the maximum force of 
contact of lips with teeth is at and near the median line, when the lips 
are alternately raised and depressed. The action of the tongue upon 
the labial faces of the teeth would be in a curved line passing across 
the labial and buccal surfaces of the teeth, beginning at the occluso- 
buccal portions of the first molars, and having its highest point at the 
necks of the central incisors. 

In the light of present knowledge, odd and isolated situations of 
areas of erosion can only be referred to localized gland affections ; the 
glands overlying the spots of erosion being alone affected. 

MORBID ANATOMY. 

It is evident that we have to do with a chemical solution of calcium 
salts as the only distinctive feature of this disorder ; the progress of the 
affection is essentially different from that of dental caries, in which 
chemical solution is but one feature. It is difficult to reconcile two 
apparently contradictory conditions in connection with erosion. It is 



EROSIONS OF THE TEETH. 



253 



believed that only an acid substance can cause the decalcification, the 
molecular destruction of the enamel and dentin, and yet it is recognized 
that the application of an acid produces roughening of the tooth-sur- 
faces ; in erosion the surfaces are frequently highly polished. 

Miller 1 states that "eroded teeth preserve 
their polish upon calcining, which shows that 
the polish pertains to the inorganic constitu- 
ents of dentin.' 7 

The general progress of the decalcification 
is as shown in Fig. 220. The enamel is first 
cupped out, usually in a transverse groove, 
which maintains its general form, increasing 
in depth and width until the dentin is ex- 
posed ; if the carious process be not grafted 

Fig. 221. 




&~ 








General direction of striae of Retzius. 



Cases of erosion of the lower 
anterior teeth (drawn from 
a cast prepared by E. D. 
Swain, of Chicago) : B, sil- 
houettes representing the 
loss of substance in five of 
the affected teeth : 1, right 
lateral incisor ; 2, right cen- 
tral; 3, left central; 4, left 
lateral ; 5, left cuspid. The 
lines a, a, a, a, a show the po- 
sition of the margin of the 
gum. A line is drawn also 
to show the original form 
of the tooth. (Black.) 



upon erosion, the excavation does not mate- 
rially alter in form. The dentin when exposed 
is usually firm and polished, and in many cases 
assumes a translucent appearance, indicative of 
structural changes. 

The shape of the excavation in the enamel 
appears to bear a somewhat close relationship 
with the striae of Retzius. These striae (see 
Chapter VII.) are lines in the enamel which 
appear to represent an orderly, regular, and 
periodical deposit of pigment in the forming tissue, and their distribu- 
tion is of such character as to mark the size of the enamel-cap at different 
periods of its formation (Fig. 221). The presence of the pigmentary 
material, whatever it may be, leads to the inference that these lines in 
the enamel differ in some degree in chemical composition from the other 
portions of the tissue ; there is possibly, or probably, some degree of 
difference in the comparative solubilities of the pigmented and non- 

1 Dental Cosmos, 1894, p. 269. 



254 AFFECTIONS OF THE ENAMEL. 

pigmented enamel. Color is lent this view if a careful examination be 
made of the form of the excavation in the early stages of a typical 
case of erosion. The base of the eroded cavity appears to lie upon suc- 
cessive striae of the enamel. The decalcification appears to proceed 
inward until one of these striae is met, which, furnishing an increased 
chemical resistance to the action of the decalcifying agent, causes the 
process of decalcification to proceed more rapidly along the lines between 
the striae. Williams l has shown that the decalcification of enamel in 
caries finds lines of greatest chemical resistance in lines of enamel-strati- 
fication. It is possible that some of these lines irregularly situated may 
govern the direction which the erosive process may take ; but characteris- 
tically they appear first to be checked and directed by the striae. 

SYMPTOMS AND DIAGNOSIS OF EROSION. 

So far as the enamel is concerned, erosion can, of course, present no 
symptoms ; it can only exhibit signs, which are the excavations them- 
selves, their forms, and the characters of their walls. When the dentin 
becomes exposed an annoying hypersensitivity is occasionally observed. 
An examination of the lip will usually reveal the labial follicles to be 
enlarged ; and if the mucous membrane be dried, a strip of blue litmus 
paper laid over it, and the lip pressed, the contents of the follicles 
will be forced out. " If the test be made in the morning, before break- 
fast, the litmus will be reddened. This acid reaction is not marked 
during the day/' 2 

The existence of erosion has become a valuable diagnostic sign for 
the general practitioner in his search for the nature of masked mala- 
dies from which patients frequently suffer. Obscure gout has been 
pointed out through dental indications alone, where the practitioner 
had before been baffled in his diagnosis. 

TREATMENT OF EROSION. 

The treatment of erosion divides itself under two heads : prophy- 
lactic and restorative ; the prophylactic is again divided into local and 
general treatment. The problem of eradicating the cause of the dis- 
order lies in a correction of the morbid glandular secretion. It is 
evident that if the irritation and altered secretion of these glands be 
due to some systemic cause, a disease of suboxidation, notably an affec- 
tion of the gout order, a cure of the local disturbance involves the 
cure of the underlying systemic cause. 

The effect of an anti-gout regimen and anti-gout therapeusis upon 
the advance of the erosion has not been sufficiently tested or observed 
to furnish reliable data in this connection ; but so far as tests have gone 
1 Dental Cosmos, 1897. 2 Truman. 



ENAMEL-STAINS. 255 

such treatment appears to lessen the formation of acid substances by 
the labial glands. Brubaker (supra) has suggested the advisability of 
destroying these glands by means of the electrocautery, as a radical 
cure of the progress of erosion. 

Next in importance to the prevention of acid formation, is its 
neutralization. This implies the application of alkalies or the use of 
alkaline mouth-washes. The greatest production of acid occurring 
during the night, applications of adhesive masses of alkaline substances 
are made to the teeth at night. The principal of these is prepared 
chalk, calcium carbonate ; it is rubbed over the labial faces of the teeth 
and between them, before retiring. It remains in sufficient amount to 
neutralize any acid substances coming in contact with it. 

Excellent results as to the checking of the progress of the decal- 
cification are obtained from the use of magnesium hydrate 1 — pre- 
cipitated magnesium hydrate held in suspension in water, milk of 
magnesia. Kirk found that three hours after the use of a teaspoonful 
of the milk of magnesia that the saliva maintained an alkaline reaction. 
It is deposited in a film over the surfaces of the teeth, making an 
alkaline coating. It should be used freely before retiring at night. 
If the patient care to take sufficient trouble, it is an excellent practice 
to dry the labial faces of the teeth each evening and paint them with a 
solution of amber in chloroform. 

Restorative Treatment. — If the cavities of erosion are treated as 
cavities of decay, excavated and filled, it is found that the erosive 
process goes on around the edges of the fillings, leaving the latter 
projecting as metallic islands from the surfaces of the teeth. Many 
operators, deeming the insertion of gold fillings unwarrantable under 
the conditions, advocate and insert zinc-phospate fillings, replacing 
them as often as necessary. The filling-material itself undergoes a 
decomposition similar to that of the enamel, so that it becomes cupped 
out. Such fillings should be well polished and varnished. If the cavi- 
ties are of proper form, porcelain or glass inlays 2 may be used with 
advantage. Like other fillings, they must be renewed when necessary. 
About the necks of the lower teeth the restorations are usually made 
with amalgam. 

Enamel-stains. 
Stains of the enamel are not to be confounded with deposits of deeply 
colored calculi, although there is no doubt some similarity in the chemi- 
cal conditions which bring about the discoloration in both instances. 
The nature and differences between these pigmentary deposits were first 
set forth by Miller, 3 but the questions involved are still sub judice. 

1 Kirk, Dental Cosmos, 1893: 2 See American Text-book of Operative Dentistry. 

3 Dental Cosmos, 1894. 



256 AFFECTIONS OF THE ENAMEL. 

METALLIC STAINS. 

Copper. — Miller found that " workers in copper, brass, or bronze 
all presented a green stain upon the upper teeth, showing every shade 
of green and bluish-green up to bluish-purple. The latter color pre- 
dominated in rooms where phosphor-bronze was worked." Attention is 
called to the fact that " trumpeters very often show a discoloration of 
the teeth." Similar discolorations are sometimes noted in proximity to 
copper-amalgam fillings. The presence of copper was demonstrated 
in scrapings from some of the stained teeth, imparting a characteristic 
green color to a Bunsen flame. 

Iron. — " Workers in iron presented stains of a brownish color." As 
pointed out, " the green salts of iron under the conditions found in the 
mouth would become oxidized and brownish in color." The administra- 
tion of iron salts medicinally is believed to produce black discolorations, 
iron sulfid being formed. " Iron deposits are usual in the border-line 
between carious and normal dentin." It is usually believed that the 
brownish spots frequently seen in connection with incipient or arrested 
caries of the underlying enamel are due to the formation of iron salts. 

Manganese. — Manganese was found in the dark -colored deposits 
upon the teeth of herbivorous animals, but as yet not upon those of 
man. The investigators state a that alkaline saliva may be necessary to 
the production of these deposits." 

Mercury. — In cases of prolonged mercurial administration the 
deposits (black) upon the teeth may give the reaction for mercury. " If 
mercury and potassium iodid are given together, the green iodid of mer- 
cury might be present upon the teeth." It is probable in these cases 
that another discoloring substance may form. There is in mercurialism 
more or less gingivitis ; the gums are swollen and spongy, bleeding 
readily. " More or less putrefactive decomposition of the albuminous 
matter present upon the teeth occurs, and hydrogen sulfid is formed. 
Reacting upon the oxyhemoglobin of the blood, sulfo-methsemoglobin 
is formed — greenish-red in concentrated, green in dilute solutions." 
Miller ascribes the discoloration found in conditions of gingivitis from 
various causes, with lack of hygienic care, to a probable reaction between 
hydrogen sulfid and oxyhemoglobin. / 

Lead. — Hirt (quoted by Miller) found in cases of lead-poisoning dis- 
colorations upon the teeth : dark brown at the necks, light brown on 
the crowns, with sometimes a trace of yellowish-green. Miller's tests 
(limited in number) showed no lead reaction from the dental deposits in 
lead-poisoning. 

Nickel. — Some of the salts of nickel are green. " Metallic nickel 
attacked by fluids of the mouth and mixtures of bread and saliva pro- 



ENAMEL-STAINS. 257 

duce greenish salts. The writer has seen the entire root of a tooth ! con- 
taining a nickel retaining-screw stained a uniform apple-green." 

Silver. — The dentin of pulpless teeth containing amalgam fillings is 
sometimes stained black, owing to the formation of silver sulfid, but 
as yet no silver deposits upon enamel have been detected. 

GREEN STAIN. 

This most common of green deposits upon enamel occurs upon both 
the temporary and the permanent teeth of young persons. The deposits 
usually have a crescentic form, are mainly upon the labial faces of the 
anterior teeth, and may be but a narrow line or may cover one-half the 
labial face. It is unusual for the deposits to extend far into the inter- 
proximal spaces, their tendency being to follow the edges of the proxi- 
mal surfaces. While green stain undoubtedly does form upon adult 
teeth (Figs. 222 and 223) where clearly the enamel-cuticle has long been 

Fig. 222. Fig. 223. 






Extension of green stain on the approximal sur- Extension of green stain on the lingual surface 
face of the incisors. (Miller.) of incisors. (Miller.) 

absent, it is only very common upon young teeth where remnants of 
Nasmyth's membrane persist about their necks. The color of these 
deposits varies from light green to greenish-black. 

If an instrument be passed over the portion of enamel affected, 
more or less roughness of the surface is evident. If the deposits are 
subjected to friction with abrasives, they disappear slowly and the 
enamel beneath is found roughened. This has led to the belief that these 
deposits cause decalcification of the enamel. It is found upon adult 
teeth that when an area- of cervico-labial enamel has become roughened 
through slight decalcification, that green stain is likely to form upon 
the rough surface, if proper hygienic care be not exercised. It is 
also found that if the stain be removed by means of abrasives, the 
roughened enamel may be readily polished — i. e., the decalcification is 
very superficial. 

If cases be observed early enough in 1 ildhood it will be noted that 

green stain is usually preceded by a lack i iene ; collections 

1 Specimen in possession < 
17 



258 AFFECTIONS OF THE ENAMEL. 

of food-debris are not removed from about the necks of the teeth, 
which implies that prior to the formation of green stain the affected 
enamel-surfaces have been subjected to the action of fermenting food- 
debris — that is, to acids. These facts have led to a general acceptance 
of the view that the roughness or decalcification has preceded the green 
deposits. " If teeth be placed in a 10 per cent, solution of hydrochloric 
acid, in from two to four minutes the enamel-cuticle begins to loosen, 
and in from five to ten minutes is isolated. It is found that the entire 
stain comes away with the cuticle." 1 

Nature of Coloring-matter. — The coloring-matter is found to be 
insoluble in water, glycerin, alcohol, ether, chloroform, and oil of tur- 
pentine. Mineral acids, hydrochloric, nitric and nitro-hydrochloric, act 
but slowly upon the coloring-matter ; even hydrochloric acid requires 
some hours to completely destroy it. Tincture of iodin, commonly be- 
lieved to act as a solvent of green stain, was found to affect it but 
slightly. Both chlorin and nascent oxygen destroy the coloring-matter 
rapidly, the cuticles being bleached in a few minutes by a 10 per cent, 
solution of hydrogen dioxid. Thick, dark-green deposits were incom- 
pletely bleached after eight hours' immersion in the 10 per cent. H 2 2 
solution, pointing to a lack of uniformity in the composition of the 
stain. 

The belief that the green coloring-matter is chlorophyll is contra- 
dicted by the fact that it is not soluble in ether. 

So far as present evidence is possessed, the association of the green 
discoloration with sulfo-methaemoglobin, or some allied substance, is 
the most probable explanation. 

Furthermore, there is no evidence that green deposits stand 
in causative relation to enamel decalcification ; as pointed out, 
they are more probably deposits, following upon limited decalci- 
fication. 

Treatment of Enamel-stains. — The general modes of treating stain- 
ing of the dentin 2 are not of general application in the treatment of 
enamel-stains. The problem in the removal of metallic stains is to 
transform an insoluble metallic salt into a soluble one. The most fre- 
quent and most practicable course in dealing with metallic stains of the 
dentin is to form soluble chlorids through the action of nascent chlorin. 
Copper, nickel, and iron stains should be treated by repeated and con- 
tinued washings with chlorin-water ; silver the same, or be acted upon 
by iodin tincture, forming soluble iodid, and so on ; but as all of these 
deposits, including green stain, are very superficial, the rational course 
of treatment is their mechanical removal by means of abrasives. A 
mixture of powdered pumice-stone and glycerin is used in conjunction 

1 Miller, Ibid. 2 American Text-book of Operative Dentistry. 



ENAMEL SOLUTION. 259 

with rapidly revolving leather wheels, brushes, and rubber cups, until 
every vestige of the deposit has disappeared and the enamel surface is 
polished. 

Enamel Solution. 

Usually the first stage of dental caries consists of a solution of the 
calcium basis of the enamel ; the decalcification is a distinctive phase 
of dental caries, and will be discussed under that head. 



CHAPTER XII. 
DISEASES OF THE DENTIN. 

The dentin, as shown in Chapters VII. and VIII., is made up of a 
matrix of calcified tissue traversed by innumerable filaments or pro- 
cesses, which are vital protoplasmic prolongations of the peripheral 
cells of the pulp. The matrix of the dentin contains two distinct 
substances, one forming a thick and uniform coating about each tubule, 
so that the dentin is traversed by as many of the coatings or sheaths 
of Neumann as there are odontoblastic processes. In addition, the 
enclosing sheaths are united laterally with one another by a material 
akin to or identical with that forming the sheaths of Neumann. It is 
believed that the substance of these sheaths is a transitional product 
which, when fully calcified, becomes the basis-substance of dentin. 
Subjected to the action of acids, the material of Neumann's sheaths is 
found much more resistant than the basis-substance of dentin. 

The relation of dentin to the odontoblasts is that of a formed product. 
So far as disease-processes are concerned, the formed material of the 
dentin must play a passive part ; although this may and probably does 
not apply to the transitional substance, the sheaths of Neumann, as 
being but a partially formed tissue it is susceptible of constructive 
change. Disorders which involve constructive nutritive changes in 
the dentin can evidently be only associated with its vital parts, which 
are the dentinal filaments, prolongations of the peripheral cells of the 
pulp. It follows, therefore, that all nutritional changes which occur in 
the dentin are directly the result of a physiological or pathological 
process in the pulp ; and associated disease-conditions are not diseases 
of dentin, strictly speaking, but are diseases of the pulp. 

Classification. — What are termed diseases of the dentin, meaning 
diseases in which the structure of the dentin undergoes changes, are 
divisible into two classes — constructive diseases and destructive dis- 
eases. The constructive diseases in an accurate classification can only be 
those conditions in which formative structural changes occur about the 
dentinal tubuli. As transitional material exists, no doubt, also about the 
transverse as well as the longitudinal processes, and as partially calcified 
tissue probably occupies many of the interglobular spaces, at least the 
possibility must be assumed of a change which could affect all of this 

260 



SECONDARY DEPOSITS. 261 

material — i. e., transform it from a partially to a completely calcified 
material. 

The formation of adventitious deposits of dentin or modified dentin 
on the surface or in the substance of the dental pulp is clearly a pro- 
cess to be included under the diseases of the pulp proper. 

The destructive diseases of the dentin are divisible, according to their 
causation, into, first, those due primarily to chemical action — erosion and 
caries ; secondly, those due to physical forces — abrasion ; thirdly, those 
due to vital causes — a resorption. In all of these the basis-substance 
of the dentin must be regarded as playing a passive part — it is a formed 
material being acted upon. 

Abrasion of the Dentin. 

The nature and character of abrasion of the teeth have been discussed 
under the head of affections of the enamel. Its progress is more rapid 
than is that of enamel abrasion. It is usually attended, particularly in 
cases of abrasion about the necks of the teeth, by an increase in the 
sensitivity of the dentinal fibrillar, and pulp reaction. 

Erosion of Dentin. 
The solution or destruction of dentin in the progress of erosion ap- 
pears to be much slower than its progress in enamel ; as in abrasion, 
a heightened sensitivity of the dentinal fibrillar is common. 

Secondary Deposits. 

It is noted in both abrasion and erosion, particularly if the progress 
of the affections be slow, that the dentin undergoes changes in appear- 
ance which are quite characteristic ; instead of having the semi-opaque- 
ness of the dentin, this tissue acquires a horn-like translucency. When 
the teeth are broken open it is common to find the pulp has receded 
from its position opposite the abrasion or erosion, the area of withdrawal 
being occupied by a deposit of dentinal substance upon the wall of the 
pulp-chamber. In cases of coronal abrasion the deposit may be uniform, 
reducing the size of the pulp-chamber at all aspects. 

It is the change from opacity to translucency which is the notable 
feature. This change is also noted normally in the dentin of aged 
persons. It has been emphasized by Miller 1 that the opacity of the 
dentin is due to the differences between the light refractive index of the 
basis-substance of the dentin and that of the dentinal tubuli. Were both 
of these of uniform composition, the dentin would be translucent. It is 
a rational inference, therefore, that the nearer to a uniform composition 
the dentin attains the more translucent it becomes. Now, as it is 

1 Micro-organisms of the Human Mouth. 



262 DISEASES OF THE DENTINE. 

physiologically out of the question that the basis-substance or formed 
dentin should become identical with the contents of the dentinal tubuli, 
there is but one inference, which is, that the tubuli acquire the nature 
of the formed dentin. It is stated, in objection to this opinion, that if 
the dentin be acted upon by dilute acids, it becomes translucent. In 
this immediate connection Miller l noted that the zone of translucency 
(see Chapter XIV.) in dental caries was not caused by decalcification, as 
that portion of the dentin contained an excess of calcium salts. These 
facts are in themselves sufficient to indicate that the appearance of trans- 
lucency in dentin is due to changes which obliterate the dentinal tubuli ; 
inferentially which cause calcification in the sheaths of Neumann and 
a recession of the odontoblastic processes. As a matter of fact, the den- 
tinal tubuli certainly do normally decrease in calibre with age. 

Positive data are wanting as to the direct causes of the appearance of 
translucency and as to exactly how the translucent dentin diifers from 
ordinary dentin in anatomical and chemical composition. From the 
examples cited, however, the evidence points to a constructive reac- 
tion of the protoplasmic portions of the dentin, to a continued stim- 
ulus ; it is a physiological defence of the pulp. It is an expression 
of cell-stimulation which evinces itself in a heightened functional 
activity — i. e., increased dentin-formation ; the hypersensitivity of the 
dentin is another evidence of increased functional activity. A similar 
or identical process is noted in connection with what is called the spon- 
taneous arrest of dental caries (see Chapter XIV.). 

Resorption of Dentin. 

Some of the features of this process will be discussed under the head 
of diseases of the pericementum, " resorption of the roots of permanent 
teeth." The normal resorption of the roots of the temporary teeth and 
the resorptions which occur upon the root-surfaces of implanted, 
replanted, or transplanted teeth, are a species of phagocytosis ; the 
tooth-tissue being removed piecemeal through the action of cells — odonto- 
clasts — which are in all probability modified leucocytes. A similar pro- 
cess is sometimes noted when the tissues about the gum- margin and the 
marginal pericementum are in a state of localized irritation or inflam- 
mation. 2 In interdental spaces where large fragments of wooden tooth- 
picks have been broken off, there has been observed a deep erosion in 
the cementum and in the dentin of the tooth, the enamel apparently being 
unaffected. The appearances in no wise resemble those of caries. In 
one case such an accident as cited resulted in resorption of the lateral 
neck-walls of an upper cuspid and bicuspid, exposing the pulp-chamber 
in a few weeks. 

1 Micro-organisms of the Human Mouth. 2 American System of Dentistry, vol. i. 



RESORPTION OF PULP-CHAMBER WALLS. 263 

Black l speaks of the process as resulting from mild irritation of the 
soft tissues, stating that as soon as pus has formed the absorptive process 
ceases. These absorptions have been noted when the evidences of trau- 
matic injury were marked, there being, however, no evidences of pus- 
formation. These were, in all probability, cases of phagocytic reaction in 
which the dental tissues were secondarily involved. The exact nature of 
the solvent formed by the cell, which brings about the solution of hard 
tissues, is not known. Krause has suggested that it may be lactic acid. 
So far as the nature of the process can be made out, it is due to the action 
of multinucleated phagocytes, which attach themselves to any substance 
to be removed, bone, dentin, etc., and resorption follows. 

Resorption of Pulp-chamber Walls. 

Gaskell 2 has reported a case where a central incisor entirely free 
from caries exhibited on its palatal aspect a pinkish tinge, which 
increased in depth until the enamel overlying crushed in, revealing 
the pulp of the tooth lying immediately beneath ; there had been a 
resorption of a large mass of the dentin lying between the pulp and 
the enamel. The pulp was removed and the tooth filled. No history 
is given as to the condition of the root, whether resorption had 
occurred there or not. Shortly after, the adjoining central incisor 
exhibited a like pink coloration, which increased, leading to the infer- 
ence that resorption was in progress in this tooth also. At the sugges- 
tion of E. C. Kirk the patient received continued doses of arsenic iodid 
and the compound syrup of the hypophosphites, in the hope of inducing 
a general and local constructive metamorphosis. This treatment was 
followed by a gradual disappearance of the pink coloration, an evidence 
of a redeposition of dentin. In the absence of histological data it is 
impossible to state just what was the nature of the repair-tissue in 
this case. 

1 American System of Dentistry, vol. i. 

2 Proc. Academy of Stomatology, Phila., 1895. 



CHAPTEE XII. (Continued). 
DENTAL CARIES. 

The last member of the group of destructive diseases of dentin is 
the all-important one of dental caries, the most universal of all diseases, 
and one from which but few civilized persons are entirely exempt. 

Definition. — Dental caries may be defined as a progressive molecu- 
lar destruction of the calcic tissues of the teeth, the first stage of which is 
a solution of the calcium salts by lactic acid ; the second, the dissolution 
of the organic matrix through the agency of saprophytic fungi. Defini- 
tions have varied according to the contemporary knowledge of the etiology 
and pathology of the disease ; the above is a pathological definition. 

History. — Examinations of crania show the disease to be certainly as 
old as semi-civilization, and when more data are obtainable it will, no 
doubt, be found even older. The skull of a mummy in the British 
Museum, dating 2800 B. C, exhibits well-marked caries and other 
dental diseases. Caries appears in the teeth of the skulls of all 
peoples, no matter what their degree of civilization, provided their 
dietary included cooked starchy foods. 

The explanations as to the nature of dental caries have undergone 
changes parallel with the advances of the collateral sciences of surgery. 
In each age or generation theories as to the origin and natural history 
of dental caries have reflected, the contemporary state and condition of 
the science of pathology ; with a modification of the theories of path- 
ology have come changes of conception as to the essential nature of the 
dental disorder. At the present time the etiology — at least the direct 
etiology — of dental caries constitutes one of the best examples in all 
medicine, of absolutely demonstrable scientific facts. 

In its indirect etiology, and in some features of its pathology and 
morbid anatomy, there is much left to be discovered ; although Miller 
has settled beyond doubt the question of its direct causation. Mil- 
ler's discoveries and demonstrations were, as all great discoveries in 
any field of science, the outcome, or an evolution from all that had 
gone before. Theories were partially formulated and set forth by pre- 
vious investigators, but it was he who furnished what science rigorously 
exacts from all her workers — direct and complete demonstration sub- 
stantiating a formulated theory. 

Investigations and opinions prior to the writings of John Hunter, 
interesting though many of them be, are necessarily purely speculative 

264 



HISTORY. 265 

in nature, for the reason that before Hunter pathology bore but a faint 
resemblance to a science, as science is now understood. Hunter/ while 
apparently inclined to classify dental caries with inflammatory disturb- 
ances, had sufficient doubt of such a position to note that caries began 
upon the outsides of teeth. The next English writers upon odon- 
tography, Fox and Bell, both regarded dental caries as an inflammatory 
disturbance, Fox believing that the disease attacked first the " lining 
membrane " of the pulp-chamber, and that the dentin deprived of its 
source of nutrition died and disintegrated. Bell 2 vigorously combated 
the theories of his predecessors, and set forth positively that caries 
always began upon the periphery of the dentin, maintaining that the 
white and colored spots upon enamel arose secondarily, and were evi- 
dences of underlying carious dentin. Also, that caries was dental gan- 
grene, and proceeded from the periphery toward the pulp. He believed 
that as soon as the pulp and crown were destroyed the caries ceased, and 
that the roots became of the nature of foreign bodies and were cast off. 

Until 1830 nearly all writers subscribed to a greater or less extent 
to the inflammatory theory of caries, which received its final blow 
in the observation that the natural crowns of teeth which had been 
mounted on plates decayed. The only vestige remaining at the present 
of a belief in the inflammatory theories of dental caries is the writings 
of Bodecker and Abbott, although their opinions have a broader founda- 
tion than those of the older observers mentioned. 

These theories may all be set aside, since it is recognized that dental 
caries proceeds in teeth whose dentin has been deprived of its source 
of nutrition. It occurs in pulpless teeth ; in human and other teeth 
mounted upon plates ; and, moreover, may be artificially produced out- 
side of the mouth. 

The next theory was radically different from the foregoing. In 
1835 Robertson, of Birmingham, England, advanced the opinion, based 
upon his observations, that it " is to chemical and not to inflammatory 
action that the destruction of the teeth must be attributed. " The 
author points out forcibly the errors and fallacies of previous writers. 
He states that 3 " Particles of food retained in fissures and imperfections 
of the teeth and in the spaces between the teeth undergo a process of 
decomposition and acquire the property of corroding, disuniting, and 
therefore destroying the earthy and animal substances of which the 
teeth are composed." 

John Tomes, a little later, was the first to record microscopic exam- 
inations of carious dentin. He described the transparent zone lying 

1 Practical Treatise on Diseases of the Teeth, 1778. 

2 Bell on The Teeth, Phila., 1830. 

3 Robertson, A Practical Treatise on the Human Teeth, 2d ed., Phila., 1839. 



266 DENTAL CARIES. 

between the carious and non-carious dentin, and observed and pointed 
out also the dentinal fibrillar. He announced the very significant fact in 
relation to caries, that l if blue litmus paper be applied to a carious 
cavity it is at once reddened, which furnishes evidence of the presence 
of an agent capable, if unresisted by the vitality of the dentin, of 
depriving the tissue of its earthy constituents, leaving the " gelatin to 
undergo a gradual decomposition favored by the heat and moisture of 
the mouth." 

Tomes first established the essentially chemical character of some 
features of caries. The character of the acid and its localization were, 
however, not ascertained. 

The electro-chemical theory of Bridgeman was the next hypothesis 
advanced ; from observation he noted that caries was more frequent in 
moist than in dry mouths, and that caries occurred more readily about 
some types of fillings than others. He believed that the tissues of the 
gum acted as the negative pole of a battery, the enamel of the tooth- 
crown as the positive element, and the fluid in which they were bathed 
as an electrolytic fluid. The difference in the electric potentiality of 
soft tissues and the tissues of the tooth-crown was deemed sufficient to 
supply the conditions of a battery. Acid substances being set free at 
the positive pole, acted as decalcifying agents. The source of the acid 
was not held to be from the electrolytic fluid, but formed by acid radicals 
set free from their combination with the calcium salts of the enamel. 
It will be seen that this theory is substantially the basis of the com- 
patibility theory of recurring caries. 

It has been maintained, principally by S. B. Palmer, that the cause 
of the recurrence of dental caries about dental fillings is due to the 
establishment of artificial electro-chemical relations ; the readiness with 
which the tooth-walls succumbed being governed by the extent of dif- 
ference of electric potentiality between filling-material and dentin. 
Recurrence of decay appeared to occur most readily about gold fillings, 
less so about tin, and least about gutta-percha, the explanation given 
being that the difference of electric potentiality is greatest between gold 
and dentin, and least between dentin and gutta-percha. The fluids of 
dentin, called of poor structure, were regarded as electrolytic in a bat- 
tery of which one element was the filling and the other the dentin ; the 
moisture of the dentin being electrically decomposed, oxygen (and 
acids) were set free, which acted as the destructive agents. These opin- 
ions, set forth by Palmer in 1874, were reiterated by him in 1894. 2 

Miller 3 examined these assumptions, and reported a long series of 
experiments relative thereto. He states that as dentin is a non- 
conductor it cannot form an element of a battery ; the fluid with 

1 Dental Surgery, 1859. 2 Dental Cosmos, Nov., 1894. 3 Ibid., 1881. 



HISTORY. 267 

which dentin is permeated is, however, a conductor. " It is always 
possible to produce an electric current by means of two liquids and 
one metal, provided that both liquids are conductors, communicate 
freely with one another, and act differently upon the metal. Hence, 
an amalgam or tin filling in a tooth with the saliva upon one side and the 
fluids of the dentin upon the other would produce a stronger current 
than with gold." " Living dentin is a better conductor than dead ; 
hence in such case metal fillings should fail sooner in contact with vital 
than with dead dentin." " Assuming that for the production of an 
electric element it is only necessary that one of them be more easily 
acted upon chemically than the other ; enamel and dentin, dentin and 
cementum, are such substances ; hence a tooth is a galvanic battery 
when in contact with saliva." 

Pieces of ivory and dentin, having the different filling materials 
inserted in them, were suspended in dilute acid for periods of weeks, 
and at the end of that time all were found affected by the acid in about 
equal degree ; had electrolytic currents been generated between the 
metals and dentin the latter would have been acted upon more vigor- 
ously in some cases than in others. 

Prior to this time the chemical theory of dental caries had received 
general acceptance, the question of the origin of the acids being still 
in doubt. Before 1868 l George Watt had advanced the mineral-acid 
theory : that decay is caused by the action of mineral acids (nitric, 
hydrochloric, and sulfuric), generated in the mouth, upon the calcic 
tissues of the teeth. Watt, using the older chemical nomenclature, 
ascribes the origin of sulfuric acid to be from H 2 S generated in putre- 
factive processes ; it is acted upon by oxygen ; sulfur is set free, which in 
a nascent state combines with oxygen, forming sulfur dioxid, in the pres- 
ence of the watery saliva becoming SO s (old nomenclature), sulfuric acid. 

" Hydrochloric acid may be free in the mouth, or may result from 
the decomposition of chlorids. Chlorin is set free, which, combining 
with hydrogen, forms HC1." 2 

Nitric acid was held to be formed from the ammonia produced in the 
process of organic decomposition ; decomposed by the action of oxygen, 
nitrogen oxids are formed, one of them being nitric acid. 

The physical appearance of the carious dentin was held to be due 
to the offending acid ; if " sulfuric acid, black decay was produced ; if 
nitric, white decay ; hydrochloric acid producing the yellow and brown 
decay." ' 6 

It is natural that in the country of Pasteur the organic acids and 
the sources of their origin in fermentation should be advanced as the 
possible causes of tooth-decalcification. Magitot pointed out that the 

1 Chemical Essays, 1868. 2 Ibid. 3 Ibid. 



268 DENTAL CARIES. 

essential phenomena of caries, as they were then understood, were the 
same in natural teeth mounted upon plates as in the natural organs 
in situ ; proving that caries is intrinsically independent of the existence 
of vitality. By immersing teeth in solutions of sugar undergoing fer- 
mentative changes he found that decalcification occurred. Teeth 
immersed in solutions of sugar in which fermentation had been pre- 
vented by boiling the solution and sealing, or by additions of sufficient 
carbolic acid, remained unaffected. 

Leber and Rottenstein, in 1867, first called attention to the probable 
causative association of bacteria with some phases of dental caries. By 
staining carious dentin with iodin the dilated dentinal tubules were 
shown to be filled with granular bodies, which they recognized as 
bacteria, identifying but one of the many forms of oral bacteria — the 
leptothrix. They deemed an initial exposure of dentin a necessary pre- 
liminary to the invasion and growth of the leptothrix, which in condi- 
tions of lessened resistance gained access to the tubules and in some 
undescribed manner caused their dilatation. 

The question of the recognition of the presence of bacteria directly 
resolves itself into the subject of special staining. Prior to the work 
of Koch, presented in 1881, no means of isolating specific bacteria by 
special cultures and staining were known, and it is remarkable that in 
the same year the essential features of dental caries were first made 
out with some degree of clearness. 

Milles and Underwood (World's Medical Congress, 1881) point out 
clearly and at length the different appearances produced by simple 
decalcification of dentin and those by dental caries. Speaking of 
Magitot's experiments, they say : " We assume that two factors have 
always been in operation : (1) the action of acids, and (2) the action of 
germs. When caries occurs in mouths it is always under circumstances 
more favorable to the action of germs than to the action of acids. " They 
believed that the acids necessary for the decalcification were excreted by 
the germs, which utilized the dentinal fibrillar as a food-supply. 

It will be seen that the invasion and multiplication of organisms in 
the tubuli were held as the antecedent of the process of decalcification. 
The deductions of these gentlemen were drawn from data not derived 
from the methods of modern bacteriology — i. e., special stains and 
special cultures. Moreover, they were made before the physiological 
chemistry of bacteria was even partially understood. 

In 1882 W. D. Miller, of Berlin, announced as the results of experi- 
ments conducted by him that he believed the first stage of dental caries 
to consist of a decalcification of the tissues of the teeth by acids which 
are for the greater part generated in the mouth by fermentation. This, 
it will be seen, is a position in agreement with that of Leber and Rotten- 



HISTORY. 269 

stein, rather than with that of Milles and Underwood. Miller's experi- 
ments 1 carry conviction with them. 

Experiment 1. — Fresh saliva, mixed with starch (1 :40) and kept at 
blood-temperature, invariably became acid in from four to five hours. 

Experiment 2. — A glass tube, 2 cm. long and 3 mm. wide, was filled 
with starch and fastened to a molar tooth on going to bed ; the next 
morning the contents of the tube had a strong acid reaction. 

Experiment 3. — When mixture was heated for half an hour at 100° C. 
and placed in an incubator it did not become acid in twenty-four hours. 

Experiment 4. — When the starch alone was heated to 150° before 
mixing, the solution became sour ; hence the ferment exists in the saliva, 
and not in the starch. 

Experiment 6. — Carbolic acid was added to saliva and starch mix- 
ture to \ per cent, strength, and put in an incubator : when tested in a 
few hours no acid was found, but sugar was in solution. 

Experiment 7. — A mixture of saliva and grape-sugar was subjected 
to a temperature of 67° C. for twenty minutes (which destroys ptyalin, 
but cannot destroy organized ferments), and placed in an incubator for 
twenty hours : the solution became acid, hence the fermentation was 
caused by an organized ferment. 

Experiment 8. — Several drops of a solution of starch and saliva CI : 40) 
were put in each of several sterilized test-tubes and sterilized. One 
tube was used as a control. One tube was infected with carious dentin : 
in twenty hours the solution was acid. From this tube a second tube was 
infected ; from the second a third, and so on : each became acid — i. e., 
an organized and reproductive ferment, producing acid, was contained 
in deep layers of carious dentin. 

Other experiments demonstrated the fungus to be independent of 
the free access of oxygen for its development. Infections by saliva of 
the above named mixture made before and after a vigorous cleansing of 
the teeth showed that the amount of acid produced after cleansing was 
often not more than one-fourth that produced by the saliva before cleans- 
ing the teeth. 

Cultures from the deeply infected dentin showed the growth of 
organisms (Fig. 224) identical in form with the bacillus acidi lactici. 
Grown upon carbohydrates, acid solutions were produced ; grown upon 
beef-extracts without carbohydrates, no acid reaction took place. 

Sections of sound dentin were placed in 5 c.c. of a neutralized 2 per 
cent, solution of beef-extract. In a second test-tube similar sections 
were placed in the same solution with the addition of 0.2 per cent, of 
cane-sugar ; both were sterilized, and then infected with a pure culture 
of the fungus under discussion. After weeks the first tube gave no acid 

1 Independent Practitioner, 1884-85. 



270 



DENTAL CARIES. 



Fig. 224. 






Fungi from carious dentin. (Miller.) 



reaction, and the dentin sections gave no evidence of softening. In 
the second tube, that containing the cane-sugar, all of the sections were 
entirely softened within three weeks, and stained sections, mounted, 

showed the tubes to be invaded by 
organisms and dilated, in some places 
the walls being broken down, forming 
caverns. 

By inducing and checking fermen- 
tation after a mixture of saliva and 
starch had acquired an acid reaction, 
filtering, and accumulating the filtered 
acid solution until a litre had been 
obtained, Miller sought to determine 
the nature of the acid present. Its 
volume was reduced over a water- 
bath to 75 c.c. ; a few drops placed 
in a dilute solution of methyl-violet 
produced no change — i. e., the acid is organic. Concentrated over the 
bath to 40 c.c, the solution was next shaken with one and one-half to 
two litres of ether, and allowed to stand until the ether became trans- 
parent ; this was then distilled until the volume was reduced to 50 c.c. 
The filtered solution was further reduced over the water-bath. An ex- 
cess of freshly prepared zinc oxid was added, the solution boiled, and 
water added until the reaction became neutral. Filtered again, the 
solution was set aside until crystallization occurred ; a drop placed 
upon a slide under the microscope showed the forms (Fig. 225) of 

crystals of zinc lactate. By testing the molec- 
ular weight of the washed and dried crystals 
it was determined clearly that the substance 
was zinc lactate. 

Miller obtained lactic acid from carious 
dentin directly. The carious dentin of seve- 
ral freshly extracted teeth was freed from 
food-debris, cut in fine pieces, placed in a test- 
tube Avith 1 c.c. of water, and 2 drops of a 10 
per cent, solution of hydrochloric acid added. 
Twenty-five c.c. of ether were then added 
and after some minutes the ether holding the lactic acid present in solu- 
tion was poured off and left standing in a test-tube twenty-four to forty- 
eight hours, until the solution was clear. Filtered and evaporated, a few- 
drops of distilled water and zinc oxid were added : crystals recognizable 
as those of zinc lactate formed. 

The character of the infecting organisms is shown in the following 



Fig. 225. 




HISTORY. 271 

manner "a beef-sugar extract is infected from the deep layers of carious 
dentin ; the solution is kept free from extraneous organisms and at a 
temperature of 37° C. The solution clouds in a few hours ; in fifteen 
hours the fermentation will have reached its most active state ; the solu- 
tion soon after begins to clear, and a flocculent colorless precipitate 
collects as a sediment upon the bottom of the vessel. The sediment 
consists of cocci and micrococci, single or in chains (Fig. 226)." These 

Fig. 226. 




fungi cause the direct splitting up of sugar without the formation of 
carbon dioxid, C 6 H 12 6 , a molecule of glucose, forming 2C 3 H ti 3 , or 
two molecules of lactic acid. 

The fungi have the power of inducing hydration of non-fermentable 
cane-sugar, converting it into fermentable levulose and dextrose — 

Ci 2 HzAi + H 2 = C 6 H 12 6 + C 6 H 12 6 

Cane-sugar. Levulose. Dextrose. 

Miller at this time deduced from his studies that the nature of the 
carious process is as follows : " Whenever solutions of sugar (nearly 
always present in the human mouth) stagnate in fissures between the 
teeth, etc., they must become acid. The acids gaining access to the dentin 
decalcify a portion of that tissue ; the tubules of the decalcified dentin 
take up the solutions of sugar and organisms which develop independent 
of the access of air. Flourishing they produce lactic acid within the 
tubules. As each layer of dentin becomes softened in time, the micro- 
organisms follow after, continually producing new acid." 

The same observer has added much to this basal doctrine since his 
original publication, which matter is considered under appropriate 
heads. The discoveries set forth are the demonstrations which con- 
vinced the dental fraternity that the essential character of the carious 
process had at last been made out. There are matters relative to the 



272 DENTAL CARIES. 

etiology, pathology, and clinical history of caries which still require 
elucidation. 

Williams 1 has supplied a missing link in the pathology and mor- 
bid anatomy of caries by demonstrating the details of caries of enamel. 
Black 2 has exploded several fallacious ideas previously held as to the 
etiology and clinical history of caries, and paved the way for a better 
understanding of the predisposing causes and variations of the active 
causes of dental caries. 

Some of the features of the morbid anatomy of dental caries, as 
shown by Miller, have been expounded by Heitzmann, Bodecker, and 
Abbott, who represent the contemporary school of believers in the in- 
flammatory origin of dental caries. The substance of the opinions of 
these gentlemen is that dental caries consists in a return of the dentin 
to its embryonic condition. The observation that dental caries may be 
artificially produced and occurs in dead dentin, exhibiting the same 
features as ordinary carious dentin, is, of course, the death-blow to this 
inflammatory theory. 

1 Dental Cosmos, 1897. 2 Ibid,, 1895. 



CHAPTER XIII. 

DENTAL CARIES: ITS CAUSES AND CLINICAL HISTORY. 

The causes of dental caries are both predisposing and exciting. 
Each of these again may be subdivided into general and local. 

Exciting Causes. 

Although it is usual to discuss the predisposing causes of a particu- 
lar disease before passing to a description of its exciting causes, the 
predisposing causes of dental caries are made more clear when the nature 
of its exciting causes is first understood. 

It has been demonstrated (see Chapter XII.) beyond reasonable 
doubt that the direct exciting cause of dental caries is lactic acid. A 
discussion of the exciting causes, therefore, involves the full consid- 
eration of the conditions of lactic fermentation in the human mouth. 
This includes two factors : first, the substances out of which lactic 
acid is formed ; and, second, the organisms which cause the trans- 
formation. 

Lactic acid is formed out of — i. e. y requires for its production the 
presence of — substances identical with, or which are under the conditions 
of the mouth converted into, glucose, C 6 H 12 6 . These are the three 
groups of carbohydrates — glucoses, C 6 H 12 6 , saccharoses, C 12 H 22 O n , and 
amyloses, C 6 H 1(( 5 . Those most common in the human dietary are 
grape-sugar or dextrose, and fruit-sugar or levulose, in the glucose 
group ; cane-sugar in the saccharose group ; starch, cellulose, and gum 
in the amylose group. 

Cane-sugar becomes converted by hydration into the two fermentable 
carbohydrates levulose and dextrose, both having the same composition, 
C 6 H 12 6 . This hydration is brought about by the action of organized 
ferments, such as ptyalin and amylopsin, which convert starch into 
glucose, 

C 6 H,A + H 2 = C 6 H, A- 

Starch Glucose. 

In order to eifect the localized and persistent fermentation of car- 
bohydrates necessary for the production of dental caries, the question 
of lodgement of ferments and fermentable materials is all important. 

18 273 



274 DENTAL CARIES. 

Given points of lodgement (see Predisposing Causes of Caries) with the 
presence of fermentable material, the next factor is the existence and 
proliferation of the ferment. Soluble carbohydrates, as cane-sugar 
(saccharose), lactose, and glucose, soluble in saliva, have their solutions 
carried into all spaces in and about the teeth ; and if ferments be pres- 
ent, organized ferments as bacteria, the solutions furnish a food-supply 
to these organisms. Insoluble or but partially soluble carbohydrates, on 
the other hand, alter the conditions. The effects of the general oral dis- 
tribution of soluble carbohydrates may be seen in the mouths of con- 
fectioners, who work amid sugar, in which evidences of general fer- 
mentation — the widespread decalcification of enamel and dentin — are 
observed. The same effects are apparent in children who are allowed 
to use sugars unstintedly. 

Perfectly soluble carbohydrates are, however, in the majority of 
cases washed away by currents of saliva, and are in all proba- 
bility removed almost entirely from about the teeth under normal 
conditions. On the contrary, insoluble carbohydrates, as solid sub- 
stances, are not washed away, except mechanically, unless they are 
transformed into soluble substances and are in situations where they 
can be subjected to the irrigating force of the saliva. It is with these 
substances that the process of caries is probably most directly asso- 
ciated. 

Caries, as has been pointed out, is not entirely a disease of civiliza- 
tion ; some savage and barbarous races are affected, and ancient races 
have also been affected. It is, however, largely a disease of civilization 
and semi-civilization ; so that the causes of its prevalence are to be 
sought for in the artificial environment of civilization. A notable 
difference between civilized and uncivilized races is in food-habit ; in 
this connection, the food-habit as regards carbohydrates is referred to. 
Judging from the data thus far presented by dental ethnologists, the 
barbarous and semi-civilized races which suffer from dental caries 
appear to be those whose dietary includes cooked starches. 

Starches in a raw state, in uncooked vegetables, are combined with 
fibrous vegetable tissue, the starch being enclosed iu capsules of cellu- 
lose. The starch is not in condition to agglutinate ; its containing 
structures crushed by the teeth, set free some of the starch-particles, 
which are mechanically separated from one another ; these particles, 
acted upon by the ptyalin of the saliva, are hydrated, becoming glucose. 
The masses are in large part or wholly washed away by the saliva and 
mechanically carried away by the vegetable cellulose of plant-skins, etc. 
By cooking, the cellulose-coverings of the starch-particles are burst ; 
the starch-particles are set free and collect in glutinous masses, which 
when taken as food are in condition to collect and remain in spaces, 



PREDISPOSING CAUSES. 275 

fissures, etc., where, being acted upon by ptvalin, glucose is formed, 
furnishing localized fermentable masses. There is another important 
consideration in this connection : many food-substances, notably fats, 
are taken at a temperature at which they are wholly or nearly fluid ; 
w T hen taken into the mouth the reduction of temperature and other 
conditions lead to their collection on, around, and between the teeth, 
which collections not only undergo changes themselves, but serve as a 
retaining medium for other debris. 

The second factor in fermentation, the first being the fermentable 
material, is the ferment itself. The conditions of the human mouth, 
under normal circumstances containing food-debris, an abundance of 
water, dead tissue, and a constant temperature, are such as to permit 
the growth of numerous micro-organisms. Variations in the conditions 
present favor or deter the development of some forms. Until the 
physiology of all the oral bacteria is clearly made out, the nature 
of the conditions favorable or deterrent to the active growth of 
definite forms can be but partially understood. One essential to the 
growth of the lactic ferment or ferments is of tolerably constant 
presence in the mouth, and yet the extent, nature, and rapidity of 
progress of dental caries vary widely in different individuals and 
apparently in different teeth of the same individual, and at different 
times in the same person. This leads to the inference that there are 
conditions which favor the growth of lactic ferments, and others which 
check it. Noting the association of the rapid progress of dental caries 
with general disease-states, it is inferred that these latter establish oral 
conditions which modify the growth of the lactic ferment. Again, in 
the absence of evident general disturbances, it is believed that local oral 
conditions which favor growth are established and disappear. 

Predisposing Causes. 

Conditions are noted which appear to bear a constant relationship 
to the progress of dental caries ; when these conditions exist caries 
is liable to occur, and when they are absent it is usually slight or ab- 
sent. These conditions are both general and local. Many of them, as 
just pointed out, are veiled in obscurity, and we have at present no 
means or data for determining the scope of their action. For example, 
why a denture almost free from caries for thirty years or more should 
suddenly fall a victim to the disease, in the absence of any change in 
the food-habit or any local anatomical changes, and with no apparent 
alteration in general nutrition, is beyond our knowledge. It is rational, 
however, to infer that conditions are present which favor the unusual 
development of the lactic ferment. The problem is one which belongs 
in the category of pathological chemistry of the cells of the entire body. 



276 DENTAL CARIES. 

GENERAL PREDISPOSING CAUSES. 

There are certain conditions in which caries is almost certain to 
increase. The most constant of these is pregnancy. Not only does 
caries increase in extent during gestation, but the rapidity of its prog- 
ress is markedly increased. In many of the cases there is a notable 
change in the dietary of the individual and commonly a lack of the 
usual hygienic care, which serve to explain the increase of caries. In 
the absence of these causes, it is evident that the explanation must be 
found in one of two conditions, or in a combination of them. Either 
attack must be increased, or resistance lessened, or both occur con- 
currently. 

The question of resistance is the resistance of the tissues of the 
teeth. It has been stated and maintained that during gestation there 
is a lessening of the calcium salts of the teeth, the reason being that 
calcium salts are robbed from the tissues of the mother to supply 
the tissues of the foetus, and that the dentin suffered as do the bones of 
the body. The enamel being a non-vital tissue, of course con-Id not 
be affected, although even decalcification of this tissue has been held 
to occur as part of the inverted nutrition. The mechanism through 
which resorption occurs is not set forth by believers in this doctrine. 
This process might act in one of two ways ; vital cells, of course, being 
a necessity for the hypothetical process. The odontoblasts upon their 
surfaces and in their filaments must be the medium through which the 
retrograde metamorphosis is accomplished, or else the usual resorptive 
cells must be the active agents — multinucleated odontoclasts. Now, as 
it is never maintained that the matrix itself loses its form, it is evident 
that the cells must then cause resorption through the dentin-substance. 
A solvent must be formed capable of abstracting the calcium salts from 
the dentin, and capable of acting through the thickness of the trans- 
formed matrix. The calcium salts taken up by the odontoblasts, or 
odontoclasts, must pass through them, to be taken up by the veins. 
It was also held that after the period of lactation a redeposition of cal- 
cium salts occurred which restored the original composition of the 
dentin The mode of formation of dentin and the character of its 
nutrition are in themselves sufficient to set aside any such hypothesis as 
the above. In addition, Black has shown x that there is no evidence to 
support a belief in the lessening of the amounts of calcium salts of the 
teeth during pregnancy, so that the matter of calcium resorption during 
pregnancy meets the fate of the inflammatory theory of caries. It 
may be mentioned, in addition, that pulpless teeth appear to break 
down rapidly in the caries of pregnancy, and as there could not by any 

1 Dental Cosmos, 1895. 



PREDISPOSING CAUSES. 211 

possibility be a retrograde metamorphosis of dead dentin, the amount 
of calcium salts in the tissue could not be a factor. 

The remaining factor for consideration is the condition of the vital 
parts of the dentin. To what extent the condition of the dentinal 
filament is an element modifying the progress of dental caries is not 
made out. Do variations in the physiological condition of these proto- 
plasmic filaments influence and modify the progress of dental caries ? 
In many or most of the cases of outbreaks of caries it is difficult or 
impossible to disassociate an increase in the local causes of caries. In 
pregnancy, in such debilitating diseases as typhoid fever and tuberculosis, 
and in other wasting disorders, there is unquestionably an increase of 
dental caries, with an increased rapidity of progress. It is this element 
of the comparative rapidity of the carious process which leads to the 
inference that the condition of the vital parts of the dentin is a govern- 
ing or modifying factor. Caries not being solely a chemical process, 
the solution of the calcium salts being but one phase of it, and the 
disorganization of the dentin-matrix another, it remains to be deter- 
mined what role the dentinal protoplasm plays. It succumbs during 
the progress of caries, and probably, like all protoplasm, offers its 
vital resistance to the action of irritants. Since it, as other proto- 
plasm, is profoundly affected by the conditions of general nutrition, 
does it offer a lessened resistance to the carious process ? Clinical 
records appear to indicate that it does. Being at the extreme peripheral 
nutritive zone, its power of resistance would be likely to be much less 
than that of more freely nourished parts, those having a vascular 
system. 

Similar conditions appear to prevail in the ansemic and leukemic 
states. It is notorious that caries runs a riotous course in diabetic 
patients (glycosuria); the formation of lactic acid in the mouths of these 
patients is abundant and widespread. 

Among the important general predisposing causes of dental caries 
must be placed heredity. Unquestionably the children of parents 
whose teeth have succumbed readily to dental caries are prone to be 
affected in a similar manner. Moreover, in many of these cases local 
conditions (environment) are not sufficient to account for the lessened 
resistance ; the evidence points to a general condition underlying the 
dental vulnerability. 

LOCAL PREDISPOSING CAUSES. 

What are termed the local predisposing causes of dental caries are 
much more evident than the general ; they include, first, variations in 
the structure, arrangement, and forms of the teeth, together with other 
local anatomical and physiological variations ; they are not actual causes, 



278 DENTAL CARIES. 

but favoring conditions. The variations of structure are macroscopic 
and microscopic, and, no doubt, variations in the chemical organization 
of the dental tissues also have a part. Any variation of structure 
which furnishes a space in which fermentable material can find lodge- 
ment is included under this head. The first of these includes fissures 
of the enamel ; these are lines of faulty enamel-formation, marking the 
bases of the cusp-segments of the teeth. Their capability of acting as 
elements of predisposition is in proportion to their depth and extent. 
They are most marked, as a rule, in the lower molars, next in the upper 
molars and bicuspids ; next in the lower bicuspids. Pits are another 
favorable lodgement-place for debris ; these are found most frequently 
at the bases of the enamel-girders of the upper incisors, at the ex- 
tremities of the sulci of bicuspids, and at the bases of the anterior 
cusps of the upper molars, and marking the extremity of the buccal 
sulci of the lower molars. Many of these enamel-defects are so 
slight as to require the use of high-power objectives to discover 
them, 1 and yet are sufficiently large to furnish lodgement for masses 
of bacteria. 

There is another feature which calls for consideration : for some 
time after the full eruption of the teeth, fragments of the partially 
calcified structure known as Nasmyth's membrane are attached to the 
teeth and occupy the depths of pits and sulci ; they, no doubt, furnish 
lodgement for ferments and fermentable material. 

If gross or even minute defects in enamel leave the dentin exposed 
at some point or points, the carious process is correspondingly favored. 
There are differences in the structure of the dentin which influence the 
rapidity and nature of the carious process. The existence of intra- 
globular spaces permits the quick progress of the disease. Differences 
of anatomical organization of the dentin itself also appear to affect the 
resistance offered by this tissue. 

Chemical analysis of the calcium constituents of dentin, enamel, ce- 
mentum, and bone shows the mineral basis of these tissues to be prob- 
ably a phosphato-carbonate of calcium (PO 4 ) 6 Ca 10 CO 3 or 3((P0 4 ) 2 Ca 3 )- 
CaC0 3 ; that is, saturated calcium phosphat-carbonate in a combina- 
tion which corresponds to apatite (PO 4 ) 6 Ca 10 Fl 2 . 2 This mineral sub- 
stance and dentin and enamel, all show different rates of solubility in 
dilute acids, the mineral substance being most soluble. In animal 
tissues the calcium salts are combined with an albuminous bases ; the 
nature of the union and the chemical composition of the " calcium 
albuminate" have not been made out. Williams 3 has shown that in the 
enamel there are two substances which differ in relative solubilities ; 
hence it is a natural inference that although both may have the same 

1 Williams, Dental Cosmos, 1897. 2 Miller. 3 Dental Cosmos, 1895. 



PREDISPOSING CAUSES. 279 

chemical composition they differ as to the molecular arrangement of 
their constituents. 

The human teeth, as shown by Black, 1 do not exhibit sufficient vari- 
ations in chemical composition to account for the differences observed 
in their decalcification during dental caries. As emphasized, " the 
variations in the amounts of salts in the dentin are not enough to 
explain their variations in hardness." 2 The hardness and solubility 
of dentin not being governed by the amount of calcium salts present, 
the differences of solubility must be looked for in the nature of the 
union between the calcium salts and the albuminous base ; that is, 
it is a question of anatomical organization of the formed product of the 
dental tissues. " In the case of a chemical union between the organic 
and inorganic constituents of a tooth we should expect to find the 
dentin hard or soft according as the union is firm or unstable." 3 

The hardness or softness of teeth, the amount of calcium salts 
they contain, or even their anatomical alterations, cannot, as shown 
by Black, prevent the advent or progress of dental caries, although 
they undoubtedly do modify its character and rate of progress. The 
forces of attack being equal, a poorly organized and badly formed 
tooth will succumb sooner than one perfectly formed and of com- 
pletely organized tissues ; this law is constant in all biology. Of 
course, such gross malformations as areas of dentin marred by lack 
of enamel-formation — honeycombed teeth — offer an inviting field for 
dental caries ; and yet in some cases such spaces may permanently 
escape caries. If the active causes of dental caries fail to assert them- 
selves, the predisposing causes signify little or nothing. However, as 
the active causes of dental caries are of almost universal distribution, it 
is rare that such tissue as described escapes. 

Faults of Form. — The outward forms of the teeth determine in a 
marked degree their vulnerability to dental caries, viewed both as to 
the separate forms, a lesser consideration, and, secondly, to the influ- 
ence that form exercises upon the contact relationships of the teeth. 

Teeth of faultless histological structure may invite the carious pro- 
cess if the pits and depressions which lie between the cusps are of un- 
usual depth. Teeth of this description are, as a rule, broad upon the 
occlusal faces as compared with their cervical widths ; hence in the 
dental arch, if the arrangement be normal, each tooth is separated from 
its fellow at the neck by a V-shaped interspace. Provided such teeth 
do not acquire roughened enamel-surfaces from the action of acids, 
locally generated, or administered medicinally, these spaces are generally 
kept free by the fluids of the mouth, which flow freely between the 
buccal and lingual cavities. If, however, the molar teeth are cuboidal 
1 Dental Cosmos, 1897. 2 Miller. '' Miller. 



280 DENTAL CARIES. 

in form, the bicuspids laterally flattened cylinders, and the incisors 
and cuspids rectangular in section, the approximal spaces have not the 
V-shaped and natural self-cleansing forms, but exhibit broad contact- 
surfaces, between which debris collects and is not removed by the saliva 
and the movements of the lips, cheeks, and tongue. The fibrous stems 
of vegetables and meat-fibres also tend to free the teeth from foreign 
matters ; raw vegetables, such as celery, and tough, fibrous meats per- 
form a useful service in this direction. 

Arrangement of the Teeth. — No matter what the forms and struc- 
ture of the teeth, if they be arranged in such a manner that uncleansible 
spaces are formed between adjoining teeth, a predisposition to caries is 
created. When, through the loss of a tooth, adjoining teeth so alter 
their positions that the natural cleansing agencies of the mouth are 
inactive, predisposition to caries is established. Teeth which have lost 
their antagonists are particularly prone to accumulate debris. This is 
marked in cases where several teeth, as the lower molars, have been 
lost ; their antagonists become the seat of food-debris deposit and of 
salivary calculi, and sooner or later suffer from degeneration of the 
pericementum. 

Other Local Predisposing" Causes. — The relative position of the 
anterior borders of the masse ter muscle with the teeth, is in some indi- 
viduals far forward, forming about the buccal surfaces of both upper 
and lower third molars a cavity partially marked off from the gen- 
eral buccal cavity. These spaces are but little affected by the irriga- 
tion of the saliva, and are out of reach of the tip of the tongue ; hence 
food-debris is likely to collect along the cervico-buccal margins of the 
teeth. 

If the frsenum of the tongue has its attachment abnormally near the 
tip, the organ is limited in its normal office ; its sweep is not sufficiently 
free, so that not only is there difficulty in mastication, but a lessening 
of tongue-cleansing of the teeth, a double cause for the accumulation 
of debris. 

Alterations in the character of the salivary and oral secretions 
may predispose to caries. It is questionable whether the saliva itself, 
as contained in the acini of the salivary glands, is ever of acid 
reaction, but it is certain that it is usually acid in reaction as found in 
the oral and buccal cavities. The mucous glands of the lips in condi- 
tions of irritation produce an acid secretion. The general distribution 
of acid in the fluids of the mouth would first exercise an influence as 
a general decalcifying agent, producing roughness or at least loss of 
polish of the enamel-surfaces, which would invite caries by affording 
lodgement for food-debris. In mouths showing an acid reaction of the 
saliva it is common to find a ropy appearance of the fluid, particu- 



CLINICAL HISTORY OF CARIES. 



281 



larly on the floor of the mouth. Mucin is precipitated by lactic acid, 
presumably the offending substance in acid saliva, and while no doubt 
the part played by the coagulated or partially coagulated mucin is in 
the formation of calculous deposits, yet coagula aid in the retention of 
food-debris. In the same manner, catarrhal conditions of the mouth 
have a part in the production of caries. In these cases there is an 
increased secretion of mucin, which acts when coagulated in the 
manner stated. 

Clinical History of Caries. 

The clinical history of dental caries records the observable phenomena 
associated with its inception, progress, and termination. 

INCEPTION OF CARIES. 

Caries usually begins upon the occlusal surfaces of the molar teeth, 
because here are usually found those defects of structure named under 
the head of predisposing causes of caries. In general terms, caries 
begins in situations which afford the most marked predisposition to it. 



Fig. 227 



Fig. 228. 



Fig. 229. 



Fig. 230. 



Fig. 231. 






Fig. 232. 



Fig. 233. 



Fig. 234. 







Fig. 237. 



Fig. 238. 



Fig. 239. 



Fig. 240. 







" The situations in which caries appears are conveniently divided under 
four heads : (1) pits, grooves, and fissures of the enamel ; (2) proximal 
surfaces ; (3) smooth surfaces which from any cause are habitually 
unclean ; (4) necks of the teeth, at or near the junction of the cement or 
enamel" (Black). 

Caries appears more frequently in the permanent first molars than in 
any other teeth. Erupted at the ages of from five and one-half to 
seven and one-half years, these teeth are in position before any of the 
temporary teeth are lost ; they are longer subjected to the attacks of 



282 DESTAL CARIES: 

caries-producing conditions, are present before the patient has learned 
to voluntarily care for the teeth, and, in addition, usually preseut 
enamel-faults or configurations which aid in the retention of food-debris. 
At this period it is unusual for the dietary to contain the substances 
which act as mechanical cleansers, or for the child to masticate with 
sufficient vigor to aid this end. The lower first molars are usually 
affected before the upper, the latter showing caries at a later period 
(Figs. 227 and 228). ' 

The upper incisor teeth, erupted next, do not, as a rule, exhibit 
marked evidences of caries so soon as the permanent second molars, 
erupted years after, although they are usually affected before the bicus- 
pids. The lower anterior teeth are the last of all to be affected, and it is 
common to see the six lower anterior teeth free from caries years after 
all of the other teeth have been lost. This is attributable to the constant 
washing these teeth receive from the saliva and to the mechanical effects 
of tongue- and lip-movement and mastication. 

If a deep basilar pit exist, as it frequently does, upon the lingual sur- 
face of the upper lateral incisor (Fig. 238), it marks this tooth for an early 
victim. The approximal surfaces of the incisors offer inviting condi- 
tions. It will be remembered that the disto-approximal walls of the 
upper incisors are much more rounded than the mesio-approximal walls ; 
hence these flattened surfaces afford a more ready lodgement for debris 
than the others. In the upper lateral incisors the mesial wall has fre- 
quently a depressed form, inviting the beginning of caries (Fig. 240). 

The upper bicuspid teeth are next *in point of vulnerability. If 
enamel-fissures exist upon the occlusal surfaces, they become the seat of 
the disease (Fig. 231) ; the pits marking the sulci-extremities of these 
teeth usually exhibit caries first. Even in the absence of these defects, 
the upper bicuspids are affected next in point of frequency, the nature 
of the contact between the bicuspids, and between bicuspids and first 
molars furnishing the lodgement for debris. 

It is usual to find caries affect the distal surface of the upper central 
incisor some time after the disease makes its appearance on the mesial 
surface of the adjoining lateral incisor (Figs. 235 and 236). For a period 
the rounded surface is kept clean, but rarely escapes infection for long. 

The mesial walls of the first molars are affected next in point of fre- 
quency, particularly if the distal wall of the second bicuspid have pre- 
viously become carious. If the occlusal faces of the lower bicuspids have 
defects of structure — pits, or in the second bicuspids fissures — they become 
affected (Fig. 232) ; but in point of usual occurrence the mesial surfaces of 
the cuspids appear to succumb next. The somewhat flattened surface in 
contact with the rounded distal Avail of the lateral incisor may invite the 
condition, or infection may occur after the appearance of caries in the 



CLINICAL HISTORY OF CARIES. 



283 



Fig. 241. 




^ 

••%, 










.. 


&~ > 




... 


V5& 




**... 






(3 




X ^o 



o 

T to 
pi 9 
a H 

*Z 

2 O 







DESCRIPTION OF CHARTS. 

These charts represent the number of carious cavities observed in one hundred person.'', and the 
position of these cavities on the individual surfaces of the teeth. There are five columns of squares 
devoted to each tooth of one side of the mouth, representing the five surfaces as shown on the left 
hand. The number of cavities in the surface represented is shown by the number of squares dark- 
ened, so that the effect of the diagram as a whole gives a striking picture of the frequency of decay 
in the individual surfaces of the several teeth. On the right the percentage, or the number per 
hundred persons, is given in figures calculated to the first decimal point. On the left the percent- 
age of cavities in the individual teeth for all surfaces is given in the same way. The cavities 



284 



DENTAL CARIES. 




o 

r I 

o > 

c 2 

1? 

ro 



# 



/<3 



'.to 







s-k b b 0, bo-k bobbO, b 



^ b~-ft. bb-bCjOoovrCC 



O SlutoOCOIafipppj) 

oo^jb^bCjC^CbobCvrb 



occurring on one side of the mouth on]y are represented. And only one decay in an individual 
surface is counted : that is, if two or more pits are found decayed in the grinding surface of a 
molar, but one is counted ; and the same rule is followed with all of the surfaces. 

Charts No. 1 and 2 (upper and lower jaw) are made up from my records of fillings for 628 per- 
sons of all ages, and therefore represent what is seen in practice rather than the actual number 
that may occur, 

Charts No. 3 and 4 (upper and lower jaw) are made from 100 of my own patients between the 
ages of ten and twenty-five years, for whom I have filled all cavities and know the condition at 
present. They represent the actual number of cases in which the individual surfaces have decayed 
in these 100 persons. (Black.) 



CLINICAL HISTORY OF CARIES. 



285 



Fig. 243. 




O O lo <-i O 



s o 0,0- < s o -o 
0, b C, C, b b b^C^b bb 



b 0,0, b b 0, 



9" V> . "^ ^ S° . N ?° ">* ^ . 

O Ob b bO bbOOOObOO 



286 



DENTAL CARIES. 



Fia. 244 








IW, 


<^ 






~/<¥ 


"%, 






n * 


.&«* 




®J x 


** s 




-4 




v 




X '?<> 


X 




\ 


^ 



o 

u 

<- z 
5 o 



Xo> 



3rd. 
Molar 



2nd. 
Molar 



1st. 
Molar 



2nd. 
Bicuspid 



1st. 

Bicuspid 



Cuspid 



Lateral 
Incisor 



Central 

Incisor 



—* 



to 

8 



• 



14 



. 



_ 






"~ 









H 



I 



bbbbii^bbbii^biiibb^bbtiibbbbbOiCibbbCiCibbbCioo 



CLINICAL HISTORY OF CARIES. 



287 



latter tooth. When the approximal face of one tooth becomes affected 
by caries it is usual to find the adjoining tooth also affected after a 
period, a natural inference when the etiology of caries is remembered. 

It is unusual for the third molars, upper or lower, to be free from 
caries many years after their eruption. Although the teeth are usually 
affected in about the order given, it is to be remembered that peculiari- 
ties of structure, form, position, and personal habits modify the occur- 
rence and progress of caries. 

The preceding charts represent records made by Black as to the 
relative frequency of dental caries. " First molars, being extracted in 
larger proportion than other teeth, the numbers given for these teeth in 
the tables are too low." 

RAPIDITY OF PROGRESS. 

All other conditions being equal, caries progresses most rapidly in 
situations where the persistent lodgement of food-debris and bacteria is 

Fig. 245. 




Section of human bicuspid, showing commencement of caries: a and a 1 , appearances caused in 
enamel and dentin by the acid of decay ; b and b-, shreds of a felt-like mass of bacteria raised 
from the surface of the enamel ; c, a cavity. X 12. (Williams.) 



assured. Hence, it progresses most rapidly when deep fissures of 
molars have invited its beginnings, in deep pits, in approximal cav- 
ities when the tooth-walls are much flattened, and upon surfaces 
which are partially overlaid by the soft tissues in such manner that 



288 DENTAL CARIES. 

the surfaces are not irrigated. Cases are frequently observed where 
the only external evidence of caries in a molar or bicuspid tooth is 
a blue-black line marking the fissure, and yet almost the entire dentin 
of the crown may be decalcified. Fig. 245 shows a bicuspid tooth 
from the mouth of a woman, aged thirty-five years, presenting no 
external evidence of caries, yet histological examination showed that 
decalcification had proceeded deeply into the substance of the dentin. 1 
" There is no doubt that many cases of so-called soft teeth have their 
softness caused by conditions similar to this." 2 

While, as a result, the extent of dentinal invasion bears some rela- 
tionship to the extent of enamel-loss, the above examples are sufficient 
in themselves to show that any preconceived opinions as to the extent 
of carious progress based upon the size of the external orifice are 
delusive. In point of fact, the most extensive decalcifications are 
usually associated with limited enamel-loss (Fig. 246, A). 

The physical appearance of the carious cavity affords some indication 
of the depth of decalcification. A cavity having slightly discolored 
ragged enamel-edges, but filled with soft debris, will usually be found 
to be deeply affected. On the contrary, cavities with broad mouths, 
but little debris, and with discolored walls, are usually associated with 
limited decalcification (Fig. 246, B). 

Approximal cavities in bicuspids and molars are more likely to be 
deep and extensive before discovery, than are approximal cavities in the 
incisors : the reason is obvious. 

While, as a rule, caries is a regularly progressive disease, going 
deeper and deeper until all of the tooth-crown is destroyed, conditions 
occur which modify its progress. If the cavity-walls be broken away 

in such manner as to permit a free circulation 
Fig. 246. of saliva in the cavity and the tendency to 

debris-accumulation is thus lessened (Fig. 246, 
B), the progress of the disease may be re- 
tarded. In some cases, indeed, it is per- 
manently checked. The latter phenomenon, 
however, is rarely observable except in teeth 
of a high grade of organization. 
Again, caries may progress rapidly for a period, and then receive a 
check to its progress. Teeth previously free from the disease may sud- 
denly fall victims to its rapid and widespread progress. No doubt, in 
many of these cases there are removed from or added to the local oral 
conditions constitutional influences which deter or favor the local devel- 
opment of caries-producing bacteria. 

While caries appears at all ages from childhood to old age, its rav- 
1 Williams. 2 Black. 





CLINICAL HISTORY OF CARIES. 289 

ages are most pronounced and its progress most rapid during the period 
of adolescence and early maturity. Its effects are most marked between 
the ages of eight and twenty-five years. As a rule, a denture which 
remains for twenty-five years unaffected by caries remains unaffected 
or but slightly affected to an indefinite age. To be sure, this im- 
plies two conditions : first, that the active causes of caries have 
been in but slight evidence ; and, secondly, that the denture is of the 
highest order. The classes of denture which escape are, perfectly formed 
and symmetrically arranged teeth, in the mouths of patients who lead 
sanitary lives, who masticate vigorously, and who escape other diseases. 
Caries beginning at the junction of the cementum and enamel of 
the teeth has a somewhat different clinical history from that noted when 
its occurrence is in other situations. Its progress is subject to great 
variations. In any of the catarrhal conditions or atrophic conditions of 
the gum which lie bare the neck-cementum caries usually occurs. It 
occurs also as a process secondary to mechanical abrasion and erosion of 
the teeth. Teeth affected by erosion, however, as has been pointed out, 
are commonly exempt from dental caries. 

19 



CHAPTER XIV. 

DENTAL CARIES : PATHOLOGY AND MORBID ANATOMY. 

The pathology of dental caries deals with the modus operandi of 
the agencies which bring about the dissolution of the calcic tissues of 
the teeth. The morbid anatomy describes the changes of structure 
which these tissues undergo in the course of the dissolution. 

The pathology of the disease varies according to the method of at- 
tack. If a break or exposure in the enamel permits access of the 

Fig. 247. 




Sections of normal human enamel, showing thick, felt-like mass of micro-organisms slightly 
raised from the surface of the tissue by pressure of the cover-glass in mounting. X 350. 
(Williams.) 



active causes of caries to the dentin, the phenomena of dentinal caries 
begin at once ; if,, however, the dentin is completely sheathed by un- 
broken enamel, dissolution of the enamel must occur before caries of 
the dentin begins. While the essential nature of enamel and dentinal 

290 



CARIES OF THE ENAMEL. 



291 



caries is nearly alike, there are distinctive differences in the modes in 
which their dissolution is brought about ; it should also be noted that 
caries of cementum exhibits anatomical peculiarities. 

Caries of the Enamel. 

For a clear understanding of caries of the enamel it is necessary to 
recall the mode of enamel-formation and its composition, which were 



Fig. 248. 




Section of carious enamel : bacteria removed tu show action of acid on enamel-rods. X Z&0. 

(Williams.) 

discovered and set forth by J. L. Williams, who furnished also the first 

accurate description of the early and later phenomena of enamel caries. 1 

The enamel is composed of two different substances, cementing-sub- 

1 It is but just to state in this connection that Miller's descriptions of the phenom- 
ena and pathology and morbid anatomy of dental caries (Micro-organisms of the Human 
Mouth) were as complete and full as the contemporary knowledge of dental histology 
could make them ; even more, his observations, correctly interpreted, anticipated some 
of the discoveries of Williams. Miller's descriptions of caries of the enamel given before 
1890 would answer, with a few modifications, for a description of our present knowledge 
of the subject. This in no way belittles the work of Williams, which must stand as a 
permanent monument to his acumen ; patience, and skill in histological technique. 



292 



DENTAL CARIES. 



stance and globules of uniform size, which are built upon one another 
until rod-like forms, the enamel-prisms, are produced. Each of these 
globules and each rod are bound together by calcified cement-substance. 
Acted upon by dilute acids, the cementing-substance is seen to be more 
soluble than the globular bodies. 

Williams has shown that felt-like adherent masses of bacteria may 
find lodgement in the remains of Nasmyth's membrane, in such situa- 

Fig. 249. 




Section of human enamel, approximal surface of incisor, showing micro-organisms of decay 
attached to the surface and marked effect upon tissue caused by penetration of acid excreted 
by the bacteria. X 250. (Williams.) 



tions as the approximal surfaces of the teeth (Fig. 247). " Lining the 
cavities or covering the surface where decay has commenced there is 
always to be seen a thick, felt-like mass of acid-forming micro-organ- 
This mass of fungi is so dense and adhesive as to make it highly 



isms. 



improbable that the enamel is affected, except in rare or special instances, by 
any acid other than that which is being excreted by the bacteria at the very 
point where they are attached to the enamel. This thick, glutinous-like 



CARIES OF THE ENAMEL. 



293 



mass of fungi also prevents the excreted acid from being washed away, 
so that it exerts its full chemical power upon calcific tissue." 

When viewed in sections, the appearances produced by the action of 
dilute lactic acid upon the enamel are similar whether the decalcification 
be artificial or due to the progress of caries. The cement-substance, 
being more soluble than the calcified globules, is dissolved first, which 

Fig. 250. 




Section of human enamel, approximal surface of molar, showing decay temporarily arrested by a 
line of stratification ; micro-organisms deeply stained. X 150. (Williams.) 



forms an irregular, roughened surface at the point of attack. The 
gradual dissolution of the cement-substance brings into relief the struc- 
ture of the enamel-rods (Fig. 248). The gradual loss of cement- 
substance unbinds the enamel-globules, which are in turn dissolved 
and washed away, leaving a depression or cavity. 

It is common to find in the early stages of enamel-caries and cavity- 
formation a discoloration of the affected tissue in those eases where the 
disease progresses very slowly. Whether this discoloration is caused by 



294 



DENTAL CARIES. 



the formation of a sulfid, 1 or is due to the action of chromogenic bacteria, 
has not been made out. 

In Fig. 249 it is seen that the advance of decalcification has brought 
into bold relief the normal pigmented lines of the enamel (the striae of 
Retzius), with the apparent indication that these lines offer territories 
of increased resistance to decalcification (see Erosion). Lines of 

Fig. 251. 




Section of carious tooth, showing appearances of decay in enamel and dentin at the line of union 
of these tissues ; the dark spots shown in the enamel and dentin at a and b are masses of micro- 
organisms. X 250. (Williams.) 



enamel-stratification may temporarily arrest the direct progress of 
enamel-dissolution (Fig. 250). Decalcification may proceed to compara- 
tively great depth before cavity-formation occurs. In fact, the decal- 
cification may penetrate the entire thickness of the enamel and dentin 
before there is breaking down of the enamel-walls. When the entire 
thickness of the enamel is penetrated and the dentin attacked there is a 
change in the mode of progress of the decalcification. It will be 
recalled that the first deposited layers of enamel are made in a layer of 
cement-substance next to the dentin ; this sheet of material appears 

1 Black. 



CARIES OF THE ENAMEL. 



295 



to offer less resistance to decalcification than other portions of the 
enamel. 

If the carious process begin in a fissure or pit, there is little or 
no tissue-loss necessary before the beginning of this secondary phase of 
enamel-caries. The solution of this interzonal layer of enamel occurs 
promptly, and decalcification proceeds along the enamel-rods from the 
dentin side with increased rapidity (Fig. 251). Bacteria growing in the 



Fig. 252. 




Cover-glass preparation from scrapings of white, opaque decaying enamel : the cement-substance 
between the rods is seen to be dissolved away, and the crevasses thus formed are filled with 
round and oval forms of micrococci and bacteria. Stained by the Gram method. 450. 
(Williams.) 

spaces from which interprismatic cement-substance has disappeared 
cause detachment of masses of partially decalcified rods (Fig. 252). 

In the ultimate breaking down of the enamel the rods first separate ; 
the outlines of the several globules of which the rods are composed are 
brought into plain view ; next, the calcified plasmic strings noted in 
enamel-formation become evident; and finally the bead-like masses 
upon these strings are left as the ultimate granular detritus of the 
enamel. 



296 



DENTAL CARIES. 



In cases of rapid enamel-dissolution Williams found streptococci 
almost invariably present ; and suggests tentatively that the variety of 



Fig. 253. 







\ 



A form of streptococcus found abundantly in mouths where very rapid decay of the teeth is in 

progress. X750. (Williams.) 

Fig. 254. 












Various forms of micrococci and bacteria from decaying enamel. Photographed by Mr. Andrew 
Pringle from Williams' cover-glass preparation. X 1000. (Williams.) 



organisms may be the factor governing the rapidity of dissolution (Figs. 



CARIES OF THE ENAMEL. 

Fig. 255. 



297 




Cover-glass preparation of scrapings from decay of enamel : shows leptothrix buccalis maxima and 
bacillus buccalis maximus of Miller. Stained by Gram method. X 850. (Williams.) 

Fig. 256. 




Scrapings of micro-organisms from the approximal surface of a decaying tooth : shows the lepto- 
thrix buccalis maxima and the bacillus buccalis maximus of Miller. X 1500. (Williams.) 



298 DENTAL CARIES. 

253 and 254). The large cocci and diplococci shown in Fig. 252 were 
always found in the backward decay of enamel. 

" In the direct caries of enamel the cavities are lined with leptothrix 
and thread-like forms " (Fig. 255). 

" The leptothrix buccalis maxima and the bacillus buccalis maximus 
of Miller are nearly always found, the latter more sparingly " (Fig. 256). 

" Beneath the felt-like masses of thread-forms and lying in contact 
with the decomposing enamel in direct decay, and also in deep cracks 
and fissures in backward decay, there is invariably found a short, thick 
bacillus, usually constricted in the centre." 

Caries of Dentin. 

Sections of carious dentin show the evidences of several processes — 
chemical, physiological, and pathological — in operation at the same time 
(Fig. 257). First, the enamel is broken down about a fissure, as shown 
in the illustration, or is dissolved from a portion of one of the tooth- 
walls (also shown). The margins of the mouth of the cavity consist of 
decalcified and discolored enamel. Between the floor of this cavity and 
the pulp-chamber are several distinct zones, each having a definite 
pathological significance. The outermost zones are soft and discolored, 
but lying beyond them next to the pulp is a translucent field, named, 
from the investigator who first called attention to it, the transparent 
zone of Tomes. In the illustration it will be noted that the trans- 
parent zone is continuous with the projection of a secondary deposit 
upon a portion of the pulp-chamber Avail. 

Upon gross examination it will be seen that for some distance from 
the mouth of the cavity and in the dentin beneath the enamel, decalcifica- 
tion has occurred, and that the formerly hard tissue has now but a carti- 
laginous density ; it is soft to cutting-instruments. After washing the 
cavity the fluid which can be squeezed out of the dentin is invariably 
acid in reaction. The more rapid destruction of dentin causes an under- 
mining of the enamel, which, being deprived of its normal support, 
suffers more or less fracture about its margins. 

" Sections made of carious dentin parallel with the direction of the 
dentinal tubuli, and stained with fuchsin, show that the superficial 
layers of the softened dentin are filled with bacterial forms ; the deeper 
layers of decalcified dentin are not infected. The decalcification pre- 
cedes the invasion of the bacteria themselves into the dentinal tubuli." 1 

How long the protoplasmic processes in the dentin retain their 
vitality when the dentin about them has been decalcified has not 
been determined. It would appear, however, from clinical tests that 
they do maintain their vitality for some time. Softened dentin is 

1 Miller. 



CARTES OF DENTIN. 



299 



often exquisitely sensitive to touch ; whether due to direct contact of 
the instrument with the dentinal processes, or due to the press- 
ure exerted being transmitted to the vital processes beyond, is not 



Fig. 257. 




Longitudinal ground-section through the crown of an inferior molar of the negro: E, enamel ; D, 
dentin ; C, cement ; p, pulp-chamber; a, large decay, from the grinding surface ; 6, small decay, 
from the mesial surface ; cs, cone of septic invasion and discoloration ; e, partially decalcified 
and discolored enamel around the carious cavity; z, dark cones: z', clearer cones ; z'p, oldest 
cones where putrefaction of the tooth cartilage begins ; c, outer transparent zone, or zone of 
Tomes ; sd, secondary dentin, caused by irritation ; s'd', secondary dentin deposited by normal 
physiological process, recession of the pulp. This figure is drawn from a ground and polished 
section mounted in Canada balsam. (Gysi.) 

known. Upon this point depends whether a dentin-matrix which has 
once undergone any degree of decalcification can ever be the seat of 
reconstructive activity. Certainly, in the absence of live protoplasm 



300 



DENTAL CARIES. 



in it, softened dentin must remain soft. Clinical records appear to 
indicate that softened dentin has, after a long period of perfect protec- 
tion, regained its hardness. This change can only be brought about 
through the agency of the odontoblastic processes, and very probably 
cannot extend beyond the boundaries of the sheaths of Neumann. 
Histological data are wanting in this connection. 

It is clearly shown that the primary ferment in dental caries per- 
forms one office : it causes removal of the calcium salts of the dentin 
in advance of the organisms. What effect it may have upon the 
organic structures remaining after complete decalcification, is question- 
able. It may or may not produce alterations in the gelatinous matrix 
which are a necessary preliminary to its future dissolution. Subsequent 
to decalcification is the destruction of the organic matrix, which is 
broken down through the agency of peptonizing bacteria. It will be 
observed that the peptonizing ferment which causes this dissolution acts 
in the presence of an acid. 

The invasion of organisms takes place via the dentinal tubnli. In 
the deeper portions of tub ides micrococci appear to predominate over 

the rod-forms, which are also present ; although 
one tubule may be filled with cocci and its 
neighbor with rod-forms (Fig. 258). It is 
only in the more superficial layers that the 
thread-forms are found in numbers. 

The invasion of the tubules is followed by 
their dilatation. This change is more plainly 
seen in sections cut at right angles to the axes 
of the tubules ; they are distended to several 
times their usual size, until there is an entire 
disappearance of the intertubular tissue (Fig. 
259). The walls of the sheaths of Neumann 
undergo thickening, this structure maintaining 



Fig. 258. 



ill I 

III 

m I 




Fig. 259. 



'*;)- 



Decayed dentin, showing a mixed 
infection with cocci and bacilli. 
X 400. (Miller.) 



Cross-section of decayed dentin : the tubules through recip- 
rocal pressure have assumed the shape of 5-6 sided 
prisms. (Miller.) 



its form to the last stage of caries, and acquiring the tobacco-stem 
appearance described by Tomes. 



CARIES OF DENTIN. 



301 



Miller points out " that the thickening of the sheath is not a vital 
process, since it may be clearly observed in specimens of artificial decay. 
In the progress of caries the thickened tubes dilate ; a contraction of 
the lumen is only found when it has occurred before softening began. 

The tubes dilate before losing their identity as tubes — i. e., they 
undergo softening. Regarding the sheaths of Neumann as transitional 
material, numerous data point to the conclusion that the calcium salts 
contained in them are held in looser bonds — i. e., are more soluble than 
the calcium salts impregnating the intertubular dentin. 

It was pointed out by Rose * (see Chapter VIII.) that what are 
called the transverse processes of the dentinal tubuli react to stains like 
the sheaths of Neumann. Williams 2 has shown that dentin is probably 
built up of globular bodies. Assuming that the process of calcification 
of dentin resembles that of enamel, and that both globules and an inter- 
globular substance are deposited in a fibrillated matrix, the appearance 
of these transverse markings would be explained as interglobular sub- 
stance becoming marked by a partial decalcification, and exhibiting a 
higher degree of solubility than the globular bodies. Rose, 3 by the 
use of the combined Koch 4 and Golgi methods of staining, found that 
these transverse branches of Neumann's sheaths do not contain proto- 
plasmic offshoots from odontoblastic processes ; they stain as solid 
masses. Therefore, the name transverse tubules is a misnomer, and 
some explanation other than tubule penetration must be found for the 
invasion of micro-organisms along these paths. 



Fig. 260. 



TUBE-CASTS. 

In the zone of decalcification in advance of bacterial invasion of the 
tubes are found rod-shaped bodies, first described by 
J. Tomes. They occur in both natural and artificial 
decay ; hence it must be inferred that their presence 
is independent of vitality in the dentin — i. e., they 
are not caused by a vital formative process. " The 
rods do not dissolve in organic acids ; neither alco- 
hol nor chloroform has any effect upon them ; but 
the addition of dilute sulfuric acid causes their quick 
dissolution. In some cases loose fragments of these 
rods may be found surrounded by cocci, the rods 
probably having been formed before dilatation of the tubes and left 
loose in the tubules by theMilatation. The rods are brittle." These fea- 
tures indicated calcic formations, but the quantity of mineral was so small 
that the formation of calcium sulfate crystals could not be made out. -5 




1 Dental Cosmos, 1893. 
3 Ibid. 



Ibid. 



2 Ibid., 1896. 
5 Miller. 



302 DENTAL CARIES. 



THE TRANSPARENT ZONE. 



Far in advance of the zone of decalcification the dentin acquires a 
translucent appearance resembling senile dentin, and having a similar 
appearance to the dentin in some cases of abrasion and erosion. Mil- 
ler's studies indicate positively that the translucent zone does not appear 
in caries of dead dentin, in artificial caries, nor in caries of human teeth 
mounted upon plates. 

Tomes and Magitot both regarded the transparency as an attempt 
made by nature to impede the progress of caries. Walkhoff regards it 
as evidence of stimulation of a formative activity, causing the production 
of intercellular substance at the expense of the cells and primarily their 
offshoots. 1 Miller showed that there is rather an increase than diminu- 
tion of the calcium salts in the transparent zone. 

It will be noted that in Fig. 257 the transparent zone is continuous 
with a new dentin -formation upon the wall of the pulp-chamber. These 
evidences point to the truth of Walkhoff 's explanation of the process, 
and indicate that the transparent appearance is the result of a vital reac- 
tion. The protoplasmic processes of the dentin being subjected to that 
degree of stimulation productive of formative activity, respond, and sec- 
ondary deposits occur. While this may be, and no doubt is, a protective 
mechanism of nature, to assert that it is a specific provision for the 
arrest of caries is perhaps overstating the degree of cell-differentiation 
involved. Clinical experience indicates, however, that transparent den- 
tin does offer increased resistance to the progress of caries. 

Cavities in which caries has ceased spontaneously exhibit frequently 
the smooth, shining appearance noted in connection with mechanical 
abrasion ; probably the sclerotic process noted above is the cause of the 
altered texture and appearance. 

Caries of Cementum. 

Decalcification appears to affect first the calcified rods known as 
Sharpey's fibres ; the saprophytic fungi, following these paths, invade 
the cementum in a manner similar to dentin invasion. The bacteria 
invade the sites of cement-corpuscles and their offshoots. 

Pigmentation in Caries. 

In the more slowly progressing cases of caries more or less discoloration 
of dentin and surrounding enamel occurs. The colors range from yellow 
to jet-black. " The intensity of the discoloration is in inverse proportion 
to the rapidity of the progress of the disease." The discolorations follow 
upon and do not precede the carious process. In limited, outlined areas 

1 Miller. 



CARIES OF DENTIN. 303 

of enamel where the primary stage of enamel-caries has begun, dis- 
coloration may occur, and the carious process be checked. Whether 
there is any connection between the pigmentation and the cessation of 
caries is not known, although in many instances this would seem to be the 
case. 

The chemical nature of these discolorations has not been made out ; 
in the cases of deep enamel-staining they appear to be due to the deposit 
of precipitates upon the area of decalcification. 

The discolorations of carious dentin may be due to the action of 
chromogenic bacteria. Miller isolated from the mouth an organism 
which he named bacillus fuscans, and " which, cultivated on the surface 
of nutritive agar-agar, imparts to the medium in a few weeks a yellowish- 
brown color, which gradually darkens and extends deeper into the sub- 
stratum as the age of the culture increases." 

The discolorations of dentin in teeth having vital pulps are probably 
not at all of similar origin to the discolorations (blue-black) of the 
dentin of pulpless teeth. 



CHAPTER XV. 

DENTAL CARIES: DIAGNOSIS, SYMPTOMS, AND PROGNOSIS. 

The diagnosis of dental caries is made through objective signs and 
subjective symptoms. The signs are the existence of cavities and of 
softened areas, directly visible or made evident through instrumental 
means. The symptoms are pains of several degrees of intensity. The 
nature and intensity of the pains furnish a guide to the depth of the 
carious invasion, and but an indirect indication of the location of the 
disease. 

Diagnosis by Objective Signs. 

Caries is to be sought for in those situations where experience, as 
recorded in the clinical history of the disease, teaches the operator to 
examine. Many cavities, particularly those of large size, are evident 
at first glance ; others require only the light of the mouth-mirror to 
show them plainly, but many require instrumental aid in the search. 
The enamel of the teeth should exhibit a hard, smooth, unbroken 
surface, and any part of its surface which will admit the point of a 
sharp exploring-instrument is defective, usually by reason of the 
presence of caries. The search for caries should be made systemati- 
cally ; and to insure thoroughness of record every discovered cavity 
should at the time of examination be recorded upon a suitable diagram. 

Mouth-mirrors are required to reflect light upon surfaces of the 
teeth, large ones being used for this purpose, and smaller ones to reflect 
the images of invisible tooth-surfaces. Exploring-instruments of vari- 
ous forms are used, having sharp points and shafts bent in such manner 
that all of the surfaces of every tooth can be traversed by the instru- 
ment-points. Floss-silk is required to pass between the teeth to detect 
areas of roughness. Wedging-appliances are also used to press apart 
contiguous teeth sufficiently to admit the exploring-instruments. A 
general survey of each tooth is made, aided by reflected light, and any 
evident cavities are recorded. 

In the absence of any directly visible cavities, an indication of their 
presence and depth may be secured by having the patient take a 
mouthful of cool — not cold — water, and, closing the mouth, to distend 
the cheeks ; if there be cavities of any depth, the presence of the water 
will usually cause pain, indefinitely located. If pain be elicited, direct 

304 



HYPERSENSITIVITY OF DENTIN. 305 

search should be made in the approximal spaces of the side to which 
the pain is referred. 

In the subsequent examination two systematic methods are pursued. 
In one method, the occlusal faces of all the teeth are first examined in 
one survey, then the interproximal spaces, and, lastly, the cervices of 
the teeth, and the margins of fillings, if there be any. In the other 
method, every portion of each tooth is examined, beginning with a 
central incisor or terminal molar, before passing to the adjoining tooth. 
The first method is more commonly followed. 

Fissures and pits in thd occlusal, buccal, or labial surfaces of the 
teeth which will admit and " catch " the points of fine exploring-instru- 
ments are defective ; when present in the teeth of youth and young 
adults, they usually overlie carious dentin. Found in the teeth of mid- 
dle-aged patients they may have little or no clinical significance. The 
basilar pits of the upper incisors require examination also. Approximal 
surfaces are first explored with exploring-points, which detect the 
presence of caries by catching the margin of a cavity or sinking into 
areas of softening. In the absence of evident cavities, some force 
should be applied to detect soft spots. Many spaces will not admit 
even fine exploring-instruments, in which cases waxed floss-silk may be 
passed between the teeth and drawn backward and forward ; if it 
" frays," it indicates the existence of an area requiring attention. The 
use of wedges, immediate or slow, may be required for further exami- 
nation of such spaces. The necks of the teeth should be examined with 
sharp points to note any softness of the tooth-tissues. The margins, 
particularly the cervical and neighboring margins, of every filling 
should be explored to test the integrity of the junction of filling 
and tooth. 

Subjective Symptoms of Caries. 

hypersensitivity of dentin. 

The exposure of dentin to external agencies is so commonly followed 
by an increase in the normal sensitivity that the condition requires 
description in itself. It ; s a general condition attendant upon abrasion, 
erosion, and caries, and has a therapeutics of its own. 

The term sensitive dentin applied to this condition is a misnomer ; 
all vital dentin is sensitive, and its degree of sensitivity differs markedly 
in individuals ; it is only when hypersensitivity is observed that the 
condition becomes pathological. 

Hypersensitivity of dentin may be defined as such a degree of 
sensitiveness as interferes with the proper excavation and shaping 
of a carious cavity ; or which, in the absence of dental ministrations, 
causes painful symptoms, as a rule reflected about neighboring parts. 

20 



306 DENTAL CARIES. 

Causes. — Normally the protoplasmic filaments of the dentin are 
completely protected from contact with external sources of irritation by 
the non-conducting layer of enamel which sheaths the crown of a 
tooth ; it receives and, in all probability, notes stimuli due to changes in 
the temperature of the enamel which are induced by the introduction of 
hot or cold substances into the mouth. In general terms, the range of 
temperature of substances introduced into the mouth should be between 
about 50° F., the temperature of spring water, and 105° F. or slightly 
higher, the temperature of cooked foods. It is a common practice 
among the majority of persons to use ice water at a temperature of 32° 
to 35° F., and to have certain food-materials served very hot, at say 
130° F. It is evident that the pulps of teeth and their terminals, 
the odontoblastic processes in the dentin, subjected to these ab- 
normal stimuli must suffer according to the degree of the frequency 
and extent of the temperature-change — i. e., the irritability of the 
parts is increased. 

It is beyond doubt that individuals differ as to the degree of normal 
dentinal sensitivity ; the dentin of one person may be cut freely without 
evidence of marked pain ; in another, the touch of an instrument to the 
newly exposed dentin is productive of a paroxysm of pain. The differ- 
ence in degree of irritability is manifested in another manner : if a mild 
sedative — for example, oil of cloves — be applied to the hypersensitive 
dentin of one person, it may remove the distressing symptoms, but with 
others it may be necessary to employ the most extreme measures to re- 
duce in any degree the hypersensitivity. 

As soon as an area of dentin loses its normal protective covering — 
the enamel, it is subjected to altered conditions, to sources of irritation 
from which it is normally free. In the majority of cases the exposure 
is brought about by the solution of overlying enamel by lactic acid. In 
others a fissure, a pit, or other malformation of the enamel may lay 
the dentin bare ; or, as is frequently noted, the recession of the gum- 
margin may expose the thin layer of cementum covering the neck of a 
tooth, and this removed by abrasion exposes the surface of the dentin 
beneath. Mechanical abrasion of the occluding faces of the teeth also 
exposes normally protected dentin to abnormal conditions. Again, 
solution of the enamel by the process known as erosion exposes the 
dentin to external sources of irritation. 

Pathology and Morbid Anatomy. — While it is true beyond ques- 
tion that the dentin is not, cannot be, the seat of inflammation, having 
no vascular system, its vital parts, the so-called dentinal fibrillse, may 
give evidence of heightened irritability, and in all probability behave as 
any other formative tissue when subjected to stimulation and irritation, 
increasing the functional activity ; giving rise, first, to hypersensitivity, 



HYPERSENSITIVITY OF DENTIN. 307 

and then to constructive action, or the formation of dentin at the 
expense of the living portions, the tubuli becoming more attenuated. 
Certain it is that some molecular change must occur in the vital parts 
as the consequence of contact with a novel environment. 

Symptoms. — The pain accompanying hypersensitivity of dentin is not 
localized to the point of affection, for the same reason that the sensations 
of the pulp, except that of throbbing, are rarely localized ; the filaments do 
not possess the true tactile sense, a sense of location. The sensation of 
pain is elicited by contact of the dentinal filaments with acid substances; 
that is, acid substances are markedly irritating to the dentinal filaments ; 
indeed, it is probable that this fact has much to do with the develop- 
ment of hypersensitivity of dentin, the acid of caries (lactic acid) 
subjecting these filaments to a constant source of irritation. The 
introduction of an acid substance into the mouth of a person who 
may have vital dentin exposed, is followed by a wave of gnawing pain, 
reflected usually along the course of contiguous nerve-filaments. The 
introduction of salt and very sweet substances is also followed by a 
similar though less marked reaction. The pressure of an instrument 
upon the dentin is attended by a flash of sharp pain, which continues 
for a time ; but lessens if the contact be maintained. In this test the 
pain is localized in the affected tooth, the touch of the instrument being 
followed by a recognition of position by the tactile organ of the tooth, 
the pericementum. The response of such teeth to thermal applications 
is increased, the absence of the non-conducting layer of enamel permit- 
ting a more rapid reduction of dentinal temperature, so that the reaction 
of the pulp is correspondingly increased. 

Diagnosis. — The only dental pain with which dental hypersensitivity 
may be confounded is pulp-pain proper. The diagnostic feature of 
pulp-pain is the reaction to changes of temperature. It is quite possible 
for marked pulp-irritation, followed by active hyperemia of that organ, 
to occur without the presence of caries in a tooth. In diagnosing the 
condition under discussion the guide is the sensation of the patient, 
search being first made in the region described by the patient as the 
seat of pain. The first observation is directed to the finding of carious 
cavities ; in the event of these being found, it is judged from the depth 
of the carious invasion whether there is a probability of pulp-disturb- 
ance. A differential test is made by contact of an instrument with the 
dentin, which, if hypersensitive, responds promptly. A drop of cool 
water is next dropped from a syringe into the cavity, when, if the 
pulp be in abnormal condition, there will be a sharp twinge of 
pain. In progressive caries this latter response is of increasing 
promptness and severity, until when the pulp is in a state of active 
hyperemia or inflammation the application of a drop of cold water 



308 DENTAL CARIES. 

is immediately followed by a paroxysm of throbbing pain. Obser- 
vation is made to determine the presence of abraded surfaces ex- 
posing the dentin, and test by touch made. It is next noted whether 
points at the necks of the teeth respond promptly to the same test. 
Attention is directed to fissures and pits which may be present and 
expose the dentin. 

Hyperemia of the pulp, in the absence of caries, is indicated by a 
sharp paroxysm of pain produced by the application of cold to the 
enamel of the tooth. 

Therapeutics. — The methods of treatment which have been followed 
for the relief of hypersensitivity of dentin, and the induction of such a 
degree of analgesia as will permit the necessary cutting of dentin, may 
be divided into general and local. 

The general means of preventing pain may be placed under three 
heads : first, the administration of agents which lessen the function of 
the pain-perceptive centres of the brain — that is, abolish perception ; 
secondly, the administration of remedies or the adoption of means to 
prevent the conveyance of painful impressions from the receptive end- 
organs to the pain-centres, or interference with transmission ; thirdly, 
the prevention of the reception of abnormal stimuli. 

The first group includes general anaesthetics and general anodynes. 
The inhalation of a few whiffs of chloroform or ethylic ether lessens 
the perception of pain. Chloroform is avoided in this connection on 
account of its dangers when used in the sitting position. Slight etheriz- 
ation, the inhalation being carried only to the benumbing-point, affords 
marked relief of the pain incidental to the cutting of hypersensitive 
dentin. 

The administration of general anodynes, particularly the combina- 
tion of morphia and atropia, has been found useful in this field : 

Ify. Morphise sulph., gr. i- ; 

Atropia? sulph., gr. T J~g-. 

M. et ft, pil. No. 1. 
S. To be taken one-half hour before operation. 

The coal-tar derivatives, phenacetin, acetanilid, and others, are occa- 
sionally efficient. The preparations known as antikamnia (said to be a 
combination of acetanilid, caffein citrate, and sodium bicarbonate) and 
ammonol (acetanilid and ammonium carbonate, equal parts ?) are to be 
preferred in this connection. The dose of the latter is gr. 10, adminis- 
tered one-half hour before operation. 

The induction of the hypnotic state belongs in the category of means 
acting upon the nerve-centres. 



HYPERSENSITIVITY OF DENTIN. 309 

Use of, Alkalies. — Ever since a belief in the chemical nature of 
dental caries has been accepted, writers upon dental pathology have 
ascribed the hypersensitivity of dentin in caries to be due to the action 
of an acid, and have advised the use of alkalies to lessen the sensitivity. 
Those generally recommended are lime-water, prepared chalk, and 
sodium bicarbonate. These agents are commonly employed in cases of 
hypersensitive dentin at the necks of teeth ; the powder is rubbed on 
and between the necks of the teeth before retiring at night. An effective 
agent of the same class is phenol sodique (sodium phenate). Used 
(diluted) as a frequent wash, it notably lessens the sensitivity of den- 
tinal filaments. It is particularly useful for children. 

Local Applications. — The usual method of treating the hyper- 
sensitivity is by the local application of analgesic agents. There are 
numerous remedies and agents which have been thus employed, and for 
convenience they may be grouped under the following headings : 

1. Dryness and heat. 

2. Cold. 

3. Those which chemically destroy the protoplasm of the dentin. 

4. Those which temporarily benumb and abolish the function of the 
receptive apparatus. 

Heat and dryness are generally applied in conjunction, dryness being 
secured by means of blasts of hot air. Dentin, which protests against 
even the touch of an instrument while wet, has its sensitivity so lessened 
after the application of a rubber-dam and drying that it may be cut 
freely, in many cases without the aid of medicinal agents. So well is 
this recognized that isolation and drying of teeth are regarded as a 
necessary preliminary to cavity-preparation. The degree of insensi- 
tivity induced is in proportion to the dryness. The drying probably 
deprives the dentinal protoplasm of a portion of its water and inhibits 
the transmission of sensation. 

Refrigeration, a well-known means of inducing local anaesthesia, 
finds application in this field. The temperature of the dentin of the 
tooth, which has been isolated by a rubber-dam, is reduced by sprays of 
highly volatile fluids ; ether and chloroform, formerly employed, have 
been displaced by the more volatile substances, ethyl chlorid and methyl 
chlorid. These agents are contained in glass tubes having a minute ori- 
fice of exit ; the cap of the vial being removed, the heat of the hand 
causes vaporization of the agent, which emerges as a fine but forcible 
spray. The full contact of the spray with the dentin should be made 
gradually to avoid painful response of the pulp. 

Agents which chemically destroy the dentinal protoplasm form the 
most extensive group of dentinal obtundents. They include salts of 
metals, such as zinc chlorid and silver nitrate ; carbolic acid and its 



310 DENTAL CARIES. 

derivatives and like bodies ; the cresols, etc. ; mineral acids, notably 
sulfuric, chromic, and nitric ; organic acids — trichloracetic and lactic 
acids (full strength), tannic acid ; alkalies — sodium and potassium 
hydrates and carbonates. 

Zinc chlorid, silver nitrate, and carbolic acid, all cause coagulation 
of the protoplasmic processes of the dentin. The mineral and organic 
acids chemically decompose both protoplasm and the calcined tissues. 
The concentrated alkalies mentioned chemically destroy protoplasm 
and bring about its quick dissolution. Like all active chemical sub- 
stances, the extent of their action depends upon the freedom with which 
they are applied. 

The caustic alkalies are used in connection with carbolic acid 
(Robinson's remedy) : 

Jfy. Potassium hydrate oim 

Sodium hydrate, V da. — M. 

Acid, carbolic, J 

Reduce the gelatinous mass formed with alcohol. 

The application of any of these agents — metallic salts (coagulants), 
mineral or organic acids, and caustic alkalies — nearly always causes 
pain, the degree of suffering being usually in proportion to the depth 
of the cavity. The cessation of the pain is an indication of proto- 
plasmic destruction. All of these agents are to be used in small 
amount and very concentrated ; dilute solutions are ineffective. Car- 
bolic acid and allied substances have an analgesic, instead of the primary 
irritating effect. They are paralyzants as well as coagulants, although 
less active than the other agents mentioned. Arsenic trioxid, arsenious 
acid, the agent used for the purpose of devitalizing the dental pulp, 
affects the protoplasm of the dentin profoundly, the effect being trans- 
mitted to the pulp, leading to the inevitable death of that organ. 

The local analgesics proper include the essential oils and the sedative 
alkaloids ; the oils of cinnamon, cloves, gaultheria, thyme. These 
exhibit the best effects in close proximity to the pulp. Thymol is the 
most powerful member of this group, and in addition is a strong anti- 
septic. The alkaloids which have been used are morphia, atropia, 
veratria, aconitia, and cocain. To be at all effective, these alkaloids 
must be used in concentrated form, so that the possible danger of 
poisoning by such powerfully toxic substances as aconitia, veratria, and 
atropia, contraindicates their general use ; moreover, they are unneces- 
sary. Morphia is ineffective. Cocain, the chief of all local anaesthetics, 
has but little effect upon hypersensitive dentinal filaments, although 
made into paste with glycerin it appears to be effective in some cases. 



HYPERSENSITIVITY OF DENTIN. 311 

Absorption of the drug by the dentinal filaments does not occur, so that 
supplementary means are necessary to carry it into the filaments. This 
is accomplished through the agency of a galvanic current. 

The tooth-pulp is excessively intolerant of changes of electric 
tension. If a tooth be perfectly isolated from its surroundings by 
means of a rubber-dam, and a very mild galvanic current be passed 
through the tooth, the positive electrode in the tooth-cavity, and 
the negative attached to the wrist or elsewhere, the pulp will respond 
promptly. If the current be continued, the response lessens, and finally 
ceases. Now, if the tension be increased by a considerable fraction of 
a volt, the pulp again protests ; but if the increase be only a minute 
fraction of a volt, the pulp does not take cognizance of it ; the voltage 
may thus, by imperceptible gradations, be raised from five volts to forty. 
The amount of electrical resistance offered by the tissues being extremely 
high, but a trifling amperage of current can pass through the tooth, 
even with forty volts pressure. If the dentin become dry, the resist- 
ance is much increased, as the only conducting-paths through the dentin 
are the dentinal tubuli when wet. Apparatus has been devised which 
permits the raising of current-tension by minute gradations, which 
has rendered available the cataphoretic use of medicaments in vital 
teeth. 

Cataphoresis (Greek kola, down, and phoreo, I bear or bring) is, 
in technical parlance, the transference of substances from the anodal or 
positive pole of a battery toward the cathodal or negative pole. Cata- 
phoresis, is to be distinguished from electrolysis, by which substances are 
decomposed and their elements carried from positive to negative, or 
from negative to positive poles, according to their polarity. In cata- 
phoresis a substance is carried unchanged from the positive toward the 
negative pole after the manner of granules in protoplasm acted upon by 
the same force (see Chapter I.). If a tooth be insulated from its 
surroundings and a pellet of cotton moistened with a strong (10 per 
cent, to 24 per cent.) solution of cocain hydrochlorid and a platinum 
anode be placed against it, the cathode being attached to the wrist, the 
cocain will, by a current of gradually increasing tension, be carried 
along the protoplasm of the dentinal tubuli and induce local paralysis 
of the sensory function. If the action be continued with an increased 
voltage, the entire pulp becomes completely anaesthetic. The volume of 
current necessary to the cataphoresis of the cocain ranges from one- 
quarter to four milliamperes. 1 The current-strength required ranges from 
five to thirty volts. Caution must be exercised to keep the cotton always 
wet, as dryness means greatly increased resistance and heat. The time 
necessary for the induction of dentinal anaesthesia ranges from about 
1 See American Text-book of Operative Dentistry. 



312 DENTAL CARIES. 

eight to twenty minutes. J. A. Woodward l suggests the use of the 
galvanic current as a diagnostic means of determining the vitality of a 
pulp. A pulpless tooth does not respond when currents of comparatively 
high tension are passed through it. 

It is customary to test the milder obtundents before resorting to 
cataphoresis. 

Certain general rules should be observed in the treatment of hyper- 
sensitive dentin : 

First. The most powerful agents, such as mineral acids, zinc chlorid, 
concentrated alkalies, etc., should never be used except in superficial 
cavities. With increase of cavity-depth milder agents may be sub- 
stituted, until, when the pulp is nearly exposed, no more active agent 
than thymol should be employed. 

Second. Resort should not be had to the active chemical agents until 
milder agents have proved inefficient. For example, zinc chlorid or 
sulfuric acid should never be the first agent used. 

Third. All cavities should be isolated and dried before using obtund- 
ing agents. 

Fourth. Arsenic should never be used unless destruction of the pulp 
is intended. 

Fifth. None but new and perfectly sharpened instruments should be 
used to cut hypersensitive dentin, and the cutting should be accomplished 
with quick, light touches. 

Prognosis of Caries. 

T 

The prognosis of dental caries is governed almost entirely by the 
thoroughness with which the indicated therapeusis is applied. In the 
absence of treatment, the disease, except in very rare cases, is con- 
tinuously progressive until the greater portion of the tooth is dis- 
integrated. Under proper and sufficient treatment the disease may be 
arrested at any stage of its progress, in any individual tooth ; but the 
arrest of the process in toto can only be secured by a removal of its 
causes, both exciting and predisposing. If the exciting causes can be 
checked or removed, the predisposing causes will be in abeyance. 
Caries will persist or recur so long as the exciting causes of the disease 
are present. 

1 Proc. Academy of Stomatology, Phila., 1896. 



CHAPTER XVI. 
DENTAL CARIES: THERAPEUTICS AND PROPHYLAXIS. 



Fig. 261. 




Figures represent the four degrees 
of carious invasion. 



It is customary to divide the course of caries into a number of 
degrees or stages, each of which represents a more or less definite 
extent of invasion in the direction of the pulp, and in each of which 
the indicated therapeusis must be modified in accordance with the con- 
ditions. The first stage or grade, called 
superficial caries, represents the lesser 
degrees of softening and invasion of den- 
tin, those cases in which as yet no evi- 
dences of any disturbance of the pulp 
have appeared. The second degree or stage 
is that in which pulp-protection forms a 
necessary part of the treatment. The 
third stage is that in which the depth of 
infection has endangered the functions or 
structure of the pulp. The fourth stage 
includes the cases of either actual invasion 
of the pulp by micro-organisms, or those 

which exhibit evidences of fatal structural changes in the vessels of 
the pulp. 

The general therapeutic principle in the treatment of dental caries is 
the removal of all softened and infected tissue and the restoration of 
the original tooth-form by means of filling-materials. This general 
therapeutic principle is modified according to the depth of carious inva- 
sion — i. e., the condition of the tissues involved. 

Filling-materials as Therapeutic Agents. 

Regarding as therapeutic agents all materials which by their physical 
or chemical properties affect the vital processes of tissues with which 
they may be brought into contact, it is evident that filling-materials 
themselves must be classed as therapeutic agents. 

The theoretically perfect filling-material is one which possesses all 
of the physical properties of dentin and enamel, but is not, like these 
substances, soluble in lactic acid. The first essential of a permanent 
filling-material is, that it must hermetically seal a cavity in which it is 
placed, and undergo no physical or chemical change which may bring 

313 



314 DENTAL CARIES. 

about a failure of the hermetical sealing ; that is, it must neither con- 
traet nor expand, and must be insoluble in organic acids, the solvents 
formed in the human mouth. It must be sufficiently hard and rigid to 
remain unaffected by the stress brought to bear upon it in mastication. 
It must be susceptible of a high polish, possess a harmonious color, and 
have a low rate of thermal conductivity. Not one of the filling- 
materials in present use possesses, in itself, all of these properties, 
although combinations of them, by adding together the individual 
virtues of single materials, remove several deficiencies of individual 
materials. 

Gold, skilfully manipulated, may be made to hermetically seal a 
cavity. It remains chemically and physically unaltered in the condi- 
tions surrounding it; properly inserted, it withstands the stress of 
mastication, and is susceptible of a high polish, but its rate of conduc- 
tivity is high, and its color is objectionable, although less so than that 
of amalgam. 

Amalgams, as found commercially, expand or contract in setting or 
hardening, so that they do not permanently seal in their hardened state 
a cavity which they exactly filled while plastic. Under the stress of 
mastication amalgam flows, so that changes in the shape of a filling 
occur. They are insoluble in the organic acids of the mouth, but are 
acted upon by sulfur compounds and probably by oxygen, so that their 
color, primarily not so harmonious as that of gold, becomes more objec- 
tionable. They have a lower rate of conductivity than gold. By 
precise formulae, properly treated * they may be made to remain stable 
as to contraction and expansion ; but except copper be added to the 
alloy, the flow of amalgam-fillings cannot be entirely checked, in 
which event discolorations are more likely. Color may be improved by 
the addition of zinc and gold to a basal alloy of silver and tin. To 
insure stability of an amalgam-filling the primary alloy must contain 
not less than 65 per cent, of silver. 2 The value of all filling-materials 
depends primarily upon the skill and care with which they are manip- 
ulated. 

It is still asserted by some homoeopathic practitioners that amalgam- 
fillings, in consequence of the free mercury contained in them, are 
instrumental in perpetuating diseases of the buccal and pharyngeal 
mucous membrane, and that obscure general disturbances are also due 
to this cause. A hardened amalgam-filling contains no free mercury ; 
all of this metal present is in chemical combination with the metals of 
the alloy. Metallic mercury is unaffected at ordinary temperatures by 
any chemical agencies found in the mouth, with the exception of sulfur 

1 See American Text-book of Operative Dentistry. 

2 Black, Dental Cosmos, 1896. 



- ii* 



THERAPEUTICS OF SUPERFICIAL CARIES. 315 

compounds ; the statement that it is the " vapor of mercury " is absurd ; 
mercury vaporizes only at a temperature of over 600° F. 

Amalgam-fillings in contact with dentin in which putrefaction is in 
progress are frequently discolored by the formation of presumably black 
sulfid of silver and perhaps salts of mercury, the dentin being stained 
black. 

Gutta-percha possesses the advantageous properties of entire non- 
conductivity, an agreeable color, comparative unchangeability in the 
fluids of the mouth, and hermetical sealing, but it is too soft to resist 
attrition and the stress of mastication. 

Zinc oxychlorid in paste (ZnO + ZnCl 2 + H 2 = 2ZnClHO) is 
irritating to the dentinal filaments, the promptness of painful response 
being directly proportionate to the cavity-depth ; it is antiseptic during 
setting and for some time subsequently ; it is a non-conductor, is Avhite, 
and when fully set is not sufficiently hard to bear the stress of mastica- 
tion ; its great drawback is its ready solubility in lactic acid. More- 
over, it shrinks in hardening. 

Zinc phosphate has an acceptable color ; its rate of conductivity is 
higher than that of zinc oxychlorid ; it does not contract in hardening, 
and is adhesive ; but its hardness is not sufficient to permanently resist the 
stress of mastication, and it is also soluble in lactic acid, although less 
so than zinc oxychlorid. The properties of zinc-phosphate cements are 
governed by the chemical composition of particular specimens and in 
large part by their mode of manipulation. 

Therapeutics of Superficial Caries. 

The therapeutics of the first stage or superficial dental caries consists 
in the thorough removal of all softened tissue, including all enamel 
which has suffered from the action of lactic acid and all dentin which 
has become secondarily affected. 

In cases of enamel caries, affecting the approximal surfaces of teeth, 
the practice has been advocated of filing away the affected enamel, 
when evident softening has not penetrated the entire thickness of the 
enamel, and polishing the cut surface, leaving, if possible, a space so 
shaped that the fluids of the mouth can wash freely through. Were it 
certain that all of the decalcified enamel could be removed by such 
means, and after operation a perfectly polished and properly shaped 
surface of unaffected enamel be left, no valid objection could be urged 
against the judicious following of the method ; but, as Williams' 1 
studies have shown, the advance of enamel caries is usually far in 
advance of the visible evidences of the decalcification ; the practice of 
filing leaves practically unchanged the pathological conditions, and 

1 Dental Cosmos, 1897. 



316 DENTAL CARIES. 

further progress of enamel decalcification at the original site is very 
likely to occur. In the light of the same discoveries, the prudent 
therapeusis is to excavate such spots of softening to the extreme margin 
of the softening. Whether or not the dentin is as yet affected, the 
excavation must be continued until sufficient dentin is invaded by the 
cutting-instruments to afford firm anchorage and support of the filling 
which is to restore the original contour. It will be observed that the 
physical and chemical properties of gold indicate it as the proper filling- 
material in these cases. 

In similar cases at a later stage, when the dentin is invaded, the 
softened dentin is to be entirely removed, and with it all of the enamel 
overlying such dentin, until the cavity formed is bounded upon all sides 
by normal dentin and enamel. The removal of all softened dentin 
renders unnecessary the use of gemicides to the dentin, as softening is 
in advance of infection. In case of dentinal hypersensitivity in these 
cases it is usual to apply carbolic acid as the first obtunding agent ; in 
which event, the same agent answers as a germicide also, but, as above 
noted, germicides are unnecessary in this stage, if excavation be thorough. 
In some cases, particularly those in which it is necessary to apply zinc 
chlorid, or even sulfuric acid, to obtund the hypersensitivity of the 
dentin, or cases in which the cataphoretic application of cocain must be 
made, the prepared dentin may become inordinately sensitive ; moreover, 
the pulp responds with dangerous promptitude to changes of tempera- 
ture. It is frequently advisable in these cases to treat the dentin as a 
wounded surface : procure surgical rest for a period ; after touching the 
cavity-walls with one of the obtundent oils, insert a perfectly neutral 
and non-conducting filling-material — gutta-percha — for a period of some 
weeks. The alternative is to apply carbolic acid to the dentinal walls, 
dry perfectly, and coat the cavity-walls with a non-conducting varnish, 
such as that called Kristalline, or Cavitine, a solution of tri-nitro-cellu- 
lose in methyl alcohol. When evaporation has left a non-conducting 
film covering the cavity-walls a gold filling may be inserted. 

A tooth in which thermal response is markedly increased through 
the presence of metallic fillings, is always to be regarded as one whose 
pulp is in danger of future disease and degeneration. The presence of 
a metallic filling in a tooth is almost certain to increase thermal response 
in some degree, but the extent and promptness should be reduced 
through the use of an intermediate non-conductor. 

Superficial caries beginning in fissures or pits of the enamel is fre- 
quently of much greater extent than is evident from the orifice of the 
cavity. If the seat be a fissure, this should always be freely and broadly 
opened from one extremity to the other, and usually it is necessary to 
cut into communicating fissures. The excavating instruments should 



THERAPEUTICS OF THE SECOND STAGE OF CARIES. 317 

follow every spot of softening until it is certain sound dentin has been 
reached in all directions, and, in addition, the enamel must be cut away 
until it is supported at all of the cavity-margins by healthy dentin. 
Cavities beginning in fissures are very deceptive as to their extent ; a 
slight fissure may communicate with such a mass of softened dentin that 
the case belongs in the second class of cavities — deep-seated instead of 
superficial caries. 

Therapeutics of the Second Stage of Caries. 

In this stage of caries there is usually, although by no means always, 
an easily discoverable cavity of size. After the removal of ragged and 
overhanging enamel-margins, and of loose debris in the cavity, it is 
noted that the response to thermal impulse is painful and prompt. In 
washing such cavities, water at a temperature of about 100° F. should 
always be used ; cold or very hot water being only employed in cavity- 
irrigation to test the promptitude of response upon the part of the pulp. 

In treating hypersensitivity of dentin in such cases the strong agents 
zinc chlorid and the mineral acids are eschewed, the strongest agent 
admissible being carbolic acid, and even the use of this agent, acting as 
it does as a coagulant, is of doubtful propriety. A perfectly safe thera- 
peusis does not admit of a stronger agent than an essential oil ; for 
example, a saturated solution of thymol in glycerin or alcohol. It may 
be necessary to seal this agent in the cavity for twenty-four hours. 
Cocain cataphoresis is, however, regarded as admissible in all stages of 
caries. 

The removal of the softened dentin in these cases forms a cavity of 
such magnitude that proximity to the pulp is evident. The softening 
has proceeded for a distance beneath the enamel, so that when all 
softened dentin is cut away from beneath the enamel the latter tissue 
overhangs, unsupported, the general cavity. These overhanging walls 
are cut away until the region of normal enamel is reached, and then it 
may be that the walls still overhang the general cavity. It is usually not 
necessary nor advisable to remove this portion of enamel. At the com- 
pletion of excavation, the pulp is found to respond immediately to even 
a current of cool air, so that protection of that organ against thermal 
impulses is an imperative demand. It is in this connection that zinc 
phosphate finds its greatest and most useful field of application. It is 
used to replace the greater bulk of the lost dentin after the following 
manner : the dentinal walls are sterilized by an application of 25 per 
cent, pyrozone (25 per cent, solution of hydrogen dioxid in ether), are 
dried, and given a coating of non-conducting varnish. The varnish 
answers a double purpose ; it lessens the moderate conductivity of the 
zinc phosphate and effectually prevents the action upon the dentinal walls 



318 DENTAL CARIES. 

of any acid impurities in the cement. Many cement-fluids contain, as 
impurity, the acid sodium (dihydrogen sodium) phosphate, NaH 2 P0 4 . 
This, when present in a cement-Ailing, causes the persistent acid reaction 
noted in some cements ; this is not only irritating to the dentinal fila- 
ments, but may cause superficial softening. Zinc phosphate, mixed 
stiff, is carefully packed against all of the cavity-walls until it is exactly 
flush with the enamel-margins and fills the cavity to near the dentin 
periphery ; the cavity in the cement is given a retentive form to hold 
the veneer filling of metal which is afterward to be inserted. 

Treatment of the Third Stage of Caries. 

In the third stage of caries complaint is made that for some time the 
presence of cool or of hot fluids in the mouth is productive of a parox- 
ysm of pain. After removing frail enamel-walls and the greater mass 
of softened dentin, including all of that underlying enamel, all of the 
decalcified peripheral dentin, it is found that further excavation would 
probably expose the pulp, which responds by painful paroxysm to even 
gentle currents of cool air. As a primary measure, even in the treat- 
ment of these conditions, irrespective of the filling operation, it is essen- 
tial that the tooth and its neighbors be placed under a rubber-dam, where 
this device can be applied. This applies with equal force to operations 
for more extensive disease ; the rubber-dam is used not only because it 
is impossible to effect perfect sterilization without it ; but, in addition, 
it is only through the dryness and clear view obtained that therapeutic 
measures can be applied with that delicacy and precision necessary to 
their successful use. 

The dentin-covering of the pulp is markedly softened, and the extent 
of bacterial invasion in the tubules is doubtful. The question arises, 
Shall excavation be made thorough, at the expense of probable pulp- 
exposure, or should it cease, and the softened dentin be permitted to 
remain ? General clinical experience speaks for the latter course. The 
cavity in its present condition is washed out with a 5 per cent, solution 
of sodium dioxid, which neutralizes any acid present and is antiseptic. 

It is evident that sterilization of the layer of dentin and pulp must 
be thoroughly effected to assure a probable success, for even under a 
perfect filling anaerobic organisms may make their way to the pulp and 
excite acute disease in that organ, which is already suffering from some 
degree of debility. Miller 1 demonstrated that the thorough steriliza- 
tion of carious dentin requires much more time than is usually given to 
it. For example, to effect the complete sterilization of a very thin 
layer of dentin requires hours' immersion in strong carbolic acid. Bac- 
teria were found in teeth which had lain in concentrated carbolic acid 

1 Dental Cosmos, 1891. 



TREATMENT OF THE FOURTH STAGE OF CARIES. 319 

for nearly two hours. Watery solutions of antiseptics were found to 
penetrate the dentin more rapidly than essential oils ; but the agents 
which effected prompt and complete sterilization, such as mercuric 
chlorid in 1-5 per cent, solution, zinc chlorid solutions, and others, are 
of questionable utility, owing to their probable deleterious action upon 
the pulp. It is preferable, therefore, to permit a harmless antiseptic 
to act for a longer period ; for example, sealing a solution of thymol in 
the cavity over night. The application of a pledget of cotton moistened 
with a 25 per cent, solution of pyrozone promptly sterilizes very thin 
layers of dentin. 

After sterilization and drying, a cavity-lining of zinc oxychlorid is 
indicated. Clinical records show that a layer of zinc oxychlorid placed 
over layers of decalcified or semi-decalcified dentin covering a pulp, are 
more frequently followed by favorable results than with any other 
material. In the light of present knowledge these benefits are attributed 
to the antiseptic property maintained by the material for some time. 
A paste of the cement is made, and a portion carried into the cavity, 
where it is immediately compressed against the cavity-walls by means 
of balls of bibulous paper which have been prepared for this pur- 
pose. All of the dentinal walls are covered to a depth of about one- 
sixteenth inch. As soon as the material has nearly set, usually in five 
to ten minutes, zinc phosphate is prepared and packed into the oxy- 
chlorid matrix, and brought flush with the cavity-margins. The 
surface-filling is then made of metal. 

Treatment of the Fourth Stage of Caries. 

The fourth stage of caries is that in which the pulp of the tooth is 
exposed before all of the decalcified dentin is removed. It is that 
stage of caries which includes in its treatment the operation of pulp- 
capping. A pulp which has been uncovered through the loss of 
overlying dentin and has been directly exposed to the fluids of the 
mouth, is almost certainly infected with micro-organisms ; but as decal- 
cification precedes bacterial invasion in caries, it is quite possible that 
the dentin covering a pulp may be decalcified before direct invasion of 
the pulp occurs. The pathologico-anatomical condition of the dental 
pulp is clinically judged by the symptomatology of the organ (see 
Chapter XVIL), and if the history of the case and the symptoms 
elicited at the time of examination give no evidence of disease of the 
organ, it is adjudged healthy, although the judgment formed may, in 
many cases, be no doubt erroneous. What is usually taken as pre- 
sumptive evidence that a pulp has not undergone serious anatomical 
degeneration, acute or chronic, is that it has never been the seat of 
acute paroxysmal pain, and that it responds promptly to a current of 



320 DENTAL CARIES. 

cold air. As will be shown in the chapter on Diseases of the Pulp, if 
paroxysms of pain have occurred, and if response to cool air is delayed, 
absent, or productive of prolonged pain, it is probable that serious 
anatomical degeneration has occurred in the pulp. 

The details of cavity-preparation are the same as in the previous 
case, except that even the slightest pressure must be avoided in operat- 
ing close to the pulp. That organ is very intolerant of even the slight- 
est pressure. The free use of hydrogen dioxid in solutions of neutral 
reaction should replace other antiseptics. The use of strong caustic or 
coagulating antiseptics, even carbolic acid, is necessarily productive of 
injury to the pulp-tissue ; the aim is to maintain the pulp in as nearly a 
normal condition as possible, not to establish an abnormal one. 

Exposed Pulp. 

An exposed pulp, even with the probability that it is non-infected 
and has suffered no serious anatomical alteration, is a condition requir- 
ing description and treatment in itself. 

Diagnosis. — Clinically, pulp-exposure is divided into, first, cases in 
which the carious process has directly exposed the organ ; secondly, 
those in which it is exposed through the removal of softened dentin 
covering it ; thirdly, those in which it has been exposedby carelessness 
or by accident in excavating. 

If the exposure be direct, it is detected visually. After isolation of 
the tooth, washing with tepid water, and drying, direct vision or a re- 
flected image in the mouth-mirror may reveal the area of exposure as a 
round space occupied by a pinkish-red body. If the exposure be large, 
pulsation of the red body may usually be observed. The exposure may 
be so slight that it is invisible, the depth of the cavity, however, indi- 
cating that exposure probably exists. Truman l advises in these cases 
that finely carded cotton be gently passed over the cavity- walls, exposure 
being detected by the momentary pain produced when the fibres pass 
over the area of exposure. A burnisher passed gently over the walls 
of a cavity in cases of suspected pnlp-exposure will usually elicit a 
quick start upon the part of the patient when the exposed spot is touched. 
The previous existence or presence of subjective symptoms, of course, 
is a diagnostic sign. 

Prognosis. — Even presuming the absence of any history of active 
pulp-disturbance, the prognoses of the three classes of cases differ ; prog- 
nosis is favorable in the reverse order of the conditions given. Again, the 
prognosis of exposed pulp is governed in great measure by the portion of 
pulp exposed ; if a cornu of the organ be the site of exposure, the prog- 
nosis is more favorable than if the body of the organ be exposed. The 

1 American System of Dentistry, vol. i. 



PULP-CAPPING. 321 

most favorable prognosis, all other conditions being alike, would asso- 
ciate with accidental exposure of a cornu of a pulp ; the most unfavor- 
able with direct exposure by carious invasion of the pulp, at or beyond, 
the neck of a tooth. 

Treatment. — Pulp-capping. — It is more desirable that a pulp- 
capping should be absolutely neutral, than that it should possess active 
therapeutic properties. Theoretically it would be desirable to induce the 
pulp to form a plate of secondary dentin which should exactly repair the 
area of exposure ; but as there is no means of exactly governing any 
stimulation which may be induced, it is preferable to use a substance 
entirely neutral therapeutically. A great number of substances have 
been recommended as pulp-cappers, but at present only two of them have 
general endorsement ; these are a cement of zinc oxysulfate and a paste 
of one of the essential oils with zinc oxid. Solutions of gutta-percha in 
chloroform, disks of softened gutta-percha, and zinc-oxychlorid cement 
are also used, but not to the extent that the first mentioned are. Zinc oxy- 
chlorid, even when the fluid is dilute, may induce irritation, but in some 
cases it has proved an admirable material. Gutta-percha preparations, 
bland as they are, do not appear to serve so well as the cement of zinc 
oxysulfate or the zinc oxid and oil paste. 

Whatever material be used, it is essential that not the slightest press- 
ure be exercised in its application. The capping-paste is best and most 
accurately carried into place through the medium of a concave metal 
disk. 

The oil and oxid paste is made by adding zinc oxid (cement powder) 
to a drop of oil of cloves until a moderately thick paste is made. The 
fluid of the oxysulfate cement is a saturated solution of zinc sulfate in 
water ; the powder is chemically pure, zinc oxid, uncalcined. If the 
powder contain traces of arsenic, pulp-devitalization may ensue. Fluid 
and powder are made into a thin paste. The cement hardens very 
quickly into a white porous body of about the hardness of plaster of 
Paris. Whichever paste is used, the concave disk is filled Avith it, the 
disk being of a size to set firmly on the dentin all around the exposure. 
It is caught upon one side in the jaws of a delicate pair of pliers and 
carried quickly to the cavity ; it is not set squarely over the exposure, 
but one edge is laid down first, and the disk delicately lowered until it 
rests upon the dentin and covers the exposure ; the excess of cement 
oozes from the side of the disk last to touch the dentin. Xo sensation 
should be caused by the operation. If zinc oxysulfate has been used, 
the surplus paste is to remain ; if the oil of cloves, the surplus is wiped 
away. The cap is retained in place and non-conductivity assured 
by lining the cavity with a layer of zinc phosphate, so thin that it will 
flow. It is the usual practice to complete the filling with zinc phos- 
21 



322 DENTAL CARIES. 

phate or gutta-percha, and if, at the end of six months, no evidences 
of disturbance have occurred and the pulp respond normally to applica- 
tions of cold, a permanent filling is inserted. 

Statistics regarding the success or failure of efforts at the conserva- 
tion of the dental pulp have been presented in such manner as to make 
their value extremely doubtful. One reports the capping of all cases 
of exposure and gives the percentage of success. Another condemns 
the operation in toto, and states that exposure always indicates imme- 
diate devitalization of the pulp, and yet in both cases the probable 
morbid anatomical conditions which are deemed to warrant either course 
are not set forth. The clinical records of those who practise the ope- 
ration after the method and under the conditions here set forth 
warrant the judicious practice of pulp-capping. No modern path- 
ologist or well-informed practitioner ever questions the great advantage 
of having vital and normal pulps in teeth ; pulpless teeth are less strong ; 
they are liable to discolorations, and prone to pericementitis, even when 
skilfully treated. 

Capped pulps may give almost immediate evidences of subjective 
disturbances, or the latter may not appear for years ; but if the pulp 
remain quiescent for a year, a successful issue is accepted. Exaggera- 
tions or alterations in the mode of reaction to thermal impulses indicate 
an unfavorable issue, as do also pains referred to the region of the 
treated tooth. 

Prophylaxis of Caries. 

The prophylaxis or prevention of dental caries implies the removal 
of its exciting and, as far as possible, its predisposing causes. The 
removal of the exciting causes implies the destruction of ferments and 
the removal of fermentable material. 

For the growth of the active causes of caries two conditions appear 
to be essential — that necessary for the life of all organisms, a food- 
supply, fermentable material ; and, secondly, some undetermined bodily 
conditions which favor or deter their growth. The manner in which 
the constitutional condition reacts upon the secretions and tissues of the 
mouth, so that favorable or unfavorable conditions exist for the growth 
of lactic ferments, is purely conjectural ; but it may be assumed that 
in a perfectly healthy individual, one having entirely normal oral con- 
ditions, the soil for the growth of organisms is most unsuitable. 

It is freely conceded that bodily states react upon the oral tissues and 
alter their physiological relation, but the chief oral disturbances are, no 
doubt, of purely local origin. While it is unquestionably true that the 
correction of morbid conditions in other parts of the body may be fol- 
lowed by a cessation of oral disturbances, the extent of the changes thus 



PROPHYLAXIS OF CARIES. 323 

brought about are not comparable, in point of extent, with the changes 
induced by rational local therapeusis. 

In general terms the prevention of dental caries begins with 
the correction of morbid physiology in all parts of the body. If 
general disease-causes — disorders of food-metabolism, of the blood- 
making organs, the blood-distributing apparatus, and the excretory 
organs — be in operation, a lowered vitality is present everywhere, 
including the mouth, and, no doubt, in the vital tissues of the teeth. 
Assuming that such causes and morbid conditions have been remedied, 
are irremediable, or not treated, the local measures are all-important. 
These are physiological, mechanical, and medicinal. The physiological 
and mechanical features both have to do with the removal of ferment- 
able material. Normally the movements of mastication subject the 
teeth to friction, through the medium of food-stuffs ; they cause an 
increased flow of saliva, which is pumped between the teeth and carried 
around and over them in currents. If the movements of mastication 
are lessened, not only is the extent of mechanical rubbing lessened, but 
the excretion of saliva is diminished, and after a time becomes altered 
in character. The coarser fibrous foods require more mastication and 
leave less debris than the soft, pulpy foods. Normal physiological use 
is, then, an important feature in the prevention of caries. If the indi- 
vidual can be persuaded to lessen the amount of cooked starches, pastry, 
etc., in the dietary, and substitute food requiring more mastication, the 
amount of fermentable debris is correspondingly reduced. 

The presence of debris between the teeth and about their necks 
affords not only in itself the material for the generation of lactic acid, 
but furnishes a medium in which soluble sugars may be retained, which 
undergo transformation into lactic acid. The importance of freeing the 
teeth from food-deposits, inspissated mucus, calculi, etc., is generally 
recognized, it having been noted that caries is markedly lessened in 
well-kept dentures. The means of accomplishing this cleansing are 
largely mechanical — by the use of tooth-picks, brushes, and floss-silk. 
The tooth-pick and floss-silk are used to partially (they cannot com- 
pletely) remove debris from the approximal surfaces of the teeth ; the 
tooth-brush removes those from the occlusal, buccal, labial, and lingual 
surfaces. Were it possible through such means to thoroughly remove 
all debris, caries might be reduced to the position of an unusual disease ; 
but it is because of their comparative inefficiency that painstaking cleans- 
ing, while lessening, does not prevent caries. 

DENTIFRICES. 

To aid the mechanical action of the tooth-brush it is usual to charge 
the brush with cleansing agents — dentifrices ; these are in the form of 



324 DENTAL CARIES. 

powders, pastes, and soaps. The powder should not be gritty ; if it 
contain sharp particles, as charcoal, pumice, etc., the powder remains in 
the small spaces between the gums and teeth and acts as an irritant. 
The usual basis of all powders is calcium carbonate, in the form of pre- 
cipitated chalk ; this serves as a mild abrasive and neutralizes any free 
acids with which it is brought in contact. Magnesium carbonate or 
hydrate is to be preferred, as its particles are smoother and have less 
tendency to collect between the teeth. It is customary to combine with 
the chalk or magnesium from one-third to one-half its bulk of orris- 
powder for the supposed tonic influence of the latter upon the soft tissues. 
To this basal powder are added flavoring-substances and sugar, to render 
the dentifrice more agreeable. Oils of lemon, gaultheria, rose, etc., are 
used for flavoring, and sugar to sweeten the powder. Sugar, however, 
should be always omitted from dentifrices ; it but adds to the ferment- 
able material present in the mouth. To sweeten dentifrices saccharin 
should be used, of which but a minute portion is required ; it is also an 
antiseptic. 

Tooth-pastes contain about the same ingredients as an ordinary 
tooth-powder, made into a paste with honey and glycerin ; their use is 
deprecated for this reason. 

Tooth-soaps have the great advantage of saponifying and removing 
the fatty deposits from the surfaces of the teeth, large areas of retention 
which are but partially cleansed by powders. They are made by adding 
about one-third by volume of powdered castile soap to ordinary tooth- 
powder. Antiseptics may be combined with tooth-soap with marked 
advantage. 

The last and a highly important consideration in the matter of pro- 
phylaxis is the destruction of the active organisms. The routine of 
tooth-cleansing includes the use of the tooth-pick, floss-silk, brush, 
and dentifrice, before the germicides proper are used. Unless the foreign 
deposits be first removed, the action of germicides is mechanically 
interfered with where they are most needed. It is essential that the 
antiseptic should be held in contact with the teeth for a long enough 
period to act as a germicide ; to merely take it into the mouth and eject 
it in a few seconds accomplishes but little good. The most effective 
method of using oral germicides is that suggested by Ottolengui, to 
spray by means of an atomizer a solution of the germicide between all 
of the teeth and over all of their surfaces. 

Miller l has tested the strength of solution of antiseptics admissible 
for this purpose, to determine which act most promptly and within the 
necessary time — about one minute : 

1 Micro-organisms of the Human Mouth. 



PROPHYLAXIS OF CARIES. 



325 



Antiseptic. 



Salicylic acid 

Benzoic acid 

Listerine 

Salicylic acid 

Bichlorid of mercury 

Benzoic acid 

Borobenzoic acid 

Thymol . . 

Bichiorid of mercury 

Peroxid of hydrogen 

Carbolic acid 

Oil of peppermint in agreeable strength 

Permanganate of potassium 

Boric acid 

Oil of wintergreen 

Tincture of cinchona . . 

Lime-water 



Concentration, 

1 :100 

1:100 



200 
2500 
200 
175 
1500 
5000 
10 per cent. 
1:100 



1 : 4000 
1:50 



1:18 



Time necessary for devi- 
talization. 



\ minute. 

i << 

4" 

Hr 

2 

1_3 « 

2 4 

1-2 minutes. 

1-2 

2-4 

2-5 
10-15 " 
10-15 " 

5-10 " 

More than 15 minutes. 
n u 15 « 

" " 15 * 
" " 15 " 
No action. 



Combinations of antiseptics are desirable to act as stimulants and, at 
times, astringents to the soft tissues. Such prescriptions as listerine, 
thymozone, borolyptol, etc. (combinations of benzoic acid, thymol, for- 
malin), and others, with such agents as eucalyptus, which exercise a 
favorable influence upon the vitality of the soft tissues, are used with 
much advantage. None but favorable results are noted after their long- 
continued use. It is customary to dilute them before using. 

The times for the thorough cleansing of the teeth should be before 
retiring and after rising, particularly the latter. The periodical cleans- 
ing of the teeth by the dental operator is an important feature in caries 
prophylaxis. 



SECTION IV. 

DISEASES OF THE DENTAL PULP. 



CHAPTER XVII. 

CONSTRUCTIVE DISEASES. 

Diseases of the dental pulp are both acute and chronic. Ac- 
cording to the anatomical features, they may also be divided into 
constructive and destructive ; and as to their character into functional 
and structural. The acute diseases are usually functional and destruc- 
tive ; in the chronic, structural and constructive changes are commonly 
noted. Constructive diseases of the dental pulp are those attended by 
the formation of deposits of new masses of dentinal substance. Destruc- 
tive diseases are those which cause retrogressive and necrotic changes in 
the tissues of the pulp. The essential difference between the two classes 
of diseases is in the mode and character of the degeneration — the one is 
acute, the other chronic. 

Pathologically there is no abrupt line of separation between those 
disorders usually termed diseases of the dental pulp and those which 
are described under the head of diseases of the live dentin. As soon as 
the dentin of the crown of a tooth is deprived of a portion of its normal 
protective covering, the enamel, either through chemical solution inci- 
dent to the first phase of dental caries, or from mechanical abrasion, the 
vital portions of the dentin are subjected to new and abnormal con- 
ditions. These vital portions being in reality prolongations of the 
peripheral cells of the pulp, it is evident that the morbid conditions en- 
gendered by their exposure are expressions of pulp-disturbance, and we 
should expect to find reactionary effects upon the part of the pulp. 
Depending upon the severity of the irritation and the length or number 
of times sources of irritation have been in operation, evidences of func- 
tional and structural disorders in the body of the dental pulp are 
observed. 

Post-mortem knowledge of structural diseases of the dental pulp is 
comparatively complete, but a parallel knowledge of the exact nature 
of the causes producing definite and recognizable conditions, together 
with the symptoms which precede and accompany the several morbid 

327 



328 CONSTRUCTIVE DISEASES. 

states, is incomplete. In the absence of precise information as to the 
association between disease-causes, their symptoms and effects, physio- 
logical and pathological, the practitioner bases his diagnosis of the ana- 
tomical condition of the pulp on symptoms which he is enabled to elicit 
by certain tests, and by the history furnished by the patient. The tests 
applied and histories obtained, direct attention to the vascular system of 
the pulp as the primary cause of many, or most, of the conditions of the 
organ which are attended by paroxysmal and reflex pains. The reac- 
tions to tests occur both with and without exposure of the pulp to exter- 
nal sources of bacterial infection, although they are found in the vast 
majority of cases where bacterial invasion is a probability. 

Symptomatology of the Pulp. 

Writers upon dental pathology, during at least the past twenty-five 
years, have called attention to the fact that pain produced through 
the irritation of the dental pulp is rarely referred to its point of 
origin ; that is, diseases of the pulp are, as a rule, characterized by 
reflected pains. G. V. Black l has clearly set forth the causes and 
reason of this phenomenon. " The pulp of a tooth is not its tactile 
organ ; that is, it does not possess the sense of location. The only 
stimulus to which it responds in its normal state, when encased in an 
unbroken chamber of dentin, which is perfectly sheathed with enamel, is 
applications of heat or cold. Far removed in its normal state from 
situations in which a tactile sense could perform any physiological 
function, such a sense would be useless. Organs in which the tactile 
sense is absent and in which it would be perhaps superfluous, when the 
seat of disease have the pain incidental to the disease reflected to other 
parts ; for example, in hip-joint disease, pain at the inner side of the 
knee is a diagnostic sign ; in inflammations of the iris the pain is referred 
to the brow ; pain at the orifice of the urethra is indicative of disease of 
the bladder, and so on. So with irritation of the dental pulp, the pain 
is indefinitely or vaguely located. In those cases where pain is referred 
to the tooth irritated, there are associated conditions which produce a 
response of the true tactile organ of the tooth, the pericementum." 

The test by which the anatomical and physiological conditions of 
the pulp are judged is the specific stimulus to which the pulp is re- 
sponsive — changes of thermal impulse. The phenomena induced by 
applications of water whose temperature is above or below that of 
the body, the extent and promptitude of the response, and the tem- 
peratures inducing it, are the only clinical means available for deter- 
mining the condition of the pulp, the prognosis of its diseases, and 
directing the mode of their treatment. 

1 American System of Dentistry, vol. i. 



SYMPTOMATOLOGY OF THE PULP. 329 

It was pointed out by Black * that if a healthy tooth be isolated by 
a double layer of rubber-dam, and a jet of water at a temperature of 
40° F. be directed against the tooth, a paroxysm of pain is produced. A 
jet of hot water will also induce a similar pain, and if the patient's eyes 
be shielded no difference in the sensations is noted. That is, the pulp 
responds to thermal stimuli, hot or cold indifferently. The organ is 
accustomed to variations of temperature between 60° and 105°-110° F., 
and within this range, in a condition of health, takes no apparent cog- 
nizance of this degree of change. 

With a decrease in the amount of dentin covering the pidp — i. e., 
with the advance of caries — the reaction to thermal stimuli increases in 
promptness, until, when the pulp is nearly exposed, the response is 
immediate. Succeeding this, is noted prompt response to lesser degrees 
of temperature-change, until the pulp comes to respond immediately to 
water at a temperature of 70° F., or thereabout, and slightly over the 
bodily temperature, 102° F. Later, another feature makes its appear- 
ance ; instead of a sharp contraction-pain, applications of moderate 
thermal stimuli are followed by a heavy, throbbing pain. Later, similar 
pains occur in the absence of tangible external sources of irritation. In 
the ordinary sequence of events intense pain is later caused by hot 
applications, and cold applications afford relief. 

The response to thermal stimuli may pursue the opposite course. 
The normally prompt response is followed by delays in reaction, until 
it is only after the continued application of cold to the exterior of a 
tooth that a paroxysm of pain is induced. In these cases there follows 
after a long time an increasing response to heat, as in the former 
instance, the reaction occurring only upon decided or prolonged heat- 
stimuli. Following upon the period of increased response to heat, in 
both cases there comes a period of quiescence, in which there is no re- 
sponse whatever to applications of intense cold, even that produced by 
the evaporation of a spray of ethyl or methyl chlorid — i. e., the sensory 
function of the pulp is paralyzed. 

These are the available subjective evidences of the anatomical con- 
dition of the pulp ; while they indicate with a degree of accuracy, use- 
ful in clinical work, the alterations in the pulp, the exact relations 
between the reactions and the morbid anatomy of the organ are not 
entirely clear. In the light of present knowledge it is assumed that, 
in consequence of loss of the normal protective covering of the pulp, its 
sensory and perhaps vasomotor nerve-fibres become stimulated, over- 
stimulated, irritated, then paralyzed by thermal stimuli in the progress 
of caries. The bloodvessels, which retained their tonus up to a certain 
point, suffer vasomotor irritation ; next, paralysis leading to their dila- 

1 American System of Dentistry, vol. i. 



330 CONSTRUCTIVE DISEASES. 

tation and to the throbbing pain. Later, even change of posture is 
sufficient to cause distention of the paralyzed vessels, hence pain in 
resuming the reclining position. Stimulation by cold, until the later 
stages, causes a sharp continuous pain, ascribed to the paroxysmal con- 
traction of the vessels ; although unquestionably specific, sensory nerve 
reaction is involved. In the stages of paralysis, heat causes further dis- 
tention of the vessels, and, if adventitious gases be present, causes their 
expansion with pressure upon nerve-filaments. 

The decreasing and delayed response to thermal stimuli must be 
referred to two sources : first, an increase in the non-conducting cover- 
ing of the pulp — i. e., a lessening of the amount of the fluid contents 
of the dentinal tubuli and a thickening of the dentinal walls, which 
necessarily implies a recession of the pulp from its normal position ; 
secondly, to degeneration of the sensory nerve-fibres themselves ; and, 
thirdly, changes in the walls of or about the bloodvessels, which check 
vasomotor response and changes in the calibre of the vessels. These 
two classes of reactions still further emphasize the division of pulp- 
diseases into two types, the acute and chronic ; the first class of reac- 
tion is associated with the acute destructive diseases, the second with 
the chronic constructive but degenerative conditions. 

Constructive Diseases of the Dental Pulp. 

The constructive diseases of the dental pulp include all the secondary 
dentin formations, tubular calcification, the formation of pulp-nodules, 
and calcareous degeneration of the pulp. 

TUBULAR CALCIFICATION. 

Definition. — By tubular calcification, or, to express the condition 
more accurately, tubular dentinification, are meant those changes that 
occur in the dentin which lead to an obliteration of the dentinal tubuli 
by constructive changes in the walls of the tubules. 

Causes and Occurrence. — A mild degree of irritation, not passing 
the stage inducing constructive metamorphosis, and apparently caused 
by heightened thermal sensitivity. It occurs in the course of mechanical 
abrasion and erosion of the teeth, under metallic fillings ; and probably 
a modification of the process precedes the slow invasion of dental caries. 
It occurs in some degree as a normal vital change due to age, and is 
common in persons who are victims of the gouty or rheumatic diathesis. 

Effects. — The altered dentin becomes translucent, acquiring a horn- 
like appearance. While there is no doubt that the existence of this 
condition of the dentin delays the disintegration of the tissue, it does 
not prevent it. 



CONSTRUCTIVE DISEASES OF THE DENTAL PULP. 



331 



SECONDARY DENTIN. 

Formations of dentinal tissue in the pulp-chamber are of several 
varieties ; the one under immediate discussion is that deposited upon 
and forming part of the pulp-chamber wall, lessening the volume of 
the cavity and of the dental pulp. 

Causes. — A lessening of the volume of the pulp-chamber — i. e., 
thickening of the dentinal walls — is a normal change of the teeth occur- 
ring with age. The change of senility is caused by a deposition of nor- 
mal dentin ; the lumen of the tubule lessens ; the odontoblasts recede, 
and grow smaller and less in number. This change is accompanied by 
increase in the fibrous elements of the pulp ; in other words, sclerotic 
changes occur with age. 

It is to be remembered that the formative activity of the pulp is not 
exhausted until the pulp is almost obliterated, and when this occurs the 
organ has completed its physiological office and undergoes degeneration. 



Fig. 262. 



Fig. 263. 





Fig. 262.— Secondary dentin, fillingthe pulp-chamber in case of abrasion of a cuspid tooth : a, portion 
lost by abrasion ; c, abraded surface ; d, secondary dentin, filling a portion of the pulp-chamber, 
and acting as a protection to the pulp; e, slender point of the pulp; irregular deposits are seen 
on the walls of the pulp-chamber, as at/; g, cylindrical calcifications in the root-portion of the 
pulp-chamber. 

Fig. 263.— Calcification, or deposit of secondary dentin, resulting from caries of an incisor : A, dia- 
gram of section of incisor, showing caries at a, and secondary dentin at b. B, illustration 
magnified 200 diameters, to show the tissue of the secondary dentin : a, pulp-chamber ; b, b, sec- 
ondary dentin ; c, primary dentin. It will be noticed that the dentinal tubes in the secondary 
dentin gradually disappear, giving place to a clear calcification. (Black.) 

As will be seen in the discussion of the several constructive changes, 
variations in the conditions of the teeth may bring about the premature 



332 



CONSTR UCTIVE DISEASES. 



exhaustion of the formative activity, with its consequence, atrophy of 
the pulp. 

The formation of secondary dentin implies the action of a localized 
stimulation of formative activity of the odontoblasts. It is probable 
that all of the cases of localized irritation may by careful investigation 
be resolved into an increased conductivity ; that is, a lessened non- 
conductivity through a denned path. 

Secondary deposits are commonly found associated with abrasion, 
erosion, the slow advance of dental caries, and with metallic fillings in 
proximity with the pulp. 

Pathology and Morbid Anatomy. — The formation is noted oppo- 
site some area of injury (Figs. 262, 263), and may be easily distin- 
guished from the normal dentin. Viewed macroscopically it is usually 
seen to differ from normal dentin in its degree of translucency (Fig. 
264), and viewed microscopically there is a sharp change of direction 

Fig. 264. 




Secondary dentin, from the same specimen as Fig. 262, magnified sufficiently to show the difference 
in primary and secondary tissue : a, abraded surface of crown : b, secondary dentin ; c, primary 
dentin ; d, junction of primary with secondary dentin ; e, remains of pulp-tissue ; /, small oval 
masses of calcific material. (Black.) 



of the tubules which abruptly marks off the secondary from the normal 
dentin. So long as the stimulation is uniform and localized, the new 
formation appears to be limited to an amount which will equalize the 
rate of conductivity in the dentin. 



CONSTRUCTIVE DISEASES OF THE DENTAL PULP. 



333 




The growth excited by caries presents some features differing markedly 
from those excited by abrasion. 1 

Growths in Abrasion. — The growths excited by abrasion have 
more regularity of structure, and the gradual obliteration of the pulp- 
chamber occurs in more regular lines (Fig. 265). In cases affecting 

double or triple rooted teeth Black found 
the deposits limited to the pulp-chamber 
and to the bulbous portions of the pulp, 
the diameter of the root-canal being 
diminished only at its entrance ; the 
deposits may extend for some distance 
up the canals, but never far, a condition 
different from that noted in deposits ex- 
cited by other causes. 

" Secondary growths in cases of abra- 

Illustration of the narrowing of the Fig-. 266. 

pulp-chamber in a molar (superior) 
by the deposit of secondary den- 
tin resulting from abrasion, showing 
the portions of the chamber in which 
the deposit usually occurs. The light- 
shaded portion (6) shows the original 
dimensions of the chamber, which in 
this instance seem to have been pret- 
ty large ; a, a point of deep abrasion ; 

c, c, remaining pulp-chamber, which 
is mostly filled with irregular masses : 

d, one of the root-canals. It will be 
observed that the narrowing of the 
root-canal is within the original pulp- 
chamber. (Black.) 

P.D., primary dentin; S.B., secondary dentin, 
P, pulp-chamber ; D, nodules. 

sion are not confined alone to the abraded teeth, but other teeth which 
have escaped wear may be affected in equal degree. In all of these 
cases there is direct evidence that the odontoblastic layer has been stimu- 
lated to increased activity and produced the regular secondary deposi- 
tion." 

Growths excited by caries usually lack the regularity observed 
in the former cases, the difference being, no doubt, attributable to the 
nature and intensity of the irritation produced. While, as shown, 
stimulation of the dental pulp results in a somewhat regular and out- 
lined functional activity, other grades of pulp-disturbance lack this 
continuous degree of response, and formations are irregular ; and by the 
same rule the existence of irregular deposits is an indication of grades 
and varieties of pulp-disturbances in excess of the stimulation ; they 
indicate irritations and hyperemias. This is well illustrated in the case 
from which the appended figure (Fig. 266) was taken. The carious 

1 Black, American System of Dentistry, vol. i. 




334 CONSTRUCTIVE DISEASES. 

process was progressing slowly in the anterior segment of an upper 
first molar, the second bicuspid being absent. When the cavity had 
reached the second stage of invasion, it was filled with zinc phosphate. 
At this time it responded normally to the thermal test. After four years, 
vague discomfort was felt in the region, and in another year was referred 
to the filled tooth, which responded faintly to hot applications and not at 
all to cold. Diagnosis : pulp in last stages of degeneration. Upon open- 
ing the tooth the portion of the chamber opposite the original caries, and 
beyond, was found much contracted by a deposit of secondary dentin ; 
the bulbous portion of the chamber and canals contained large loose 
dentinal tumors, that in the palatal root almost filling the canal. These 
deposits were of conglomerate nature, the elements of pulp-tissue being 
caught in their substance. 

The formation of regular deposits of secondary dentin, causing 
uniform or nearly uniform contraction of the pulp-chamber, has no 
clinical significance in point of. therapeutical indications. The process 
must be regarded as conservative in character, although unquestionably 
the formation of secondary dentin hastens the physiological exhaustion 
of the pulp-tissue. Black l calls specific attention to the changes in the 
character of extensive secondary deposits, that at first the new structure 
contains nearly the normal number of tubules, which later become fewer 
— L e., the odontoblasts have lessened in number and later structureless 
granular dentinal matter is found. 

Other forms of calcic deposits are found in the pulp-chamber, 
mechanically displacing portions of the pulp-substance, occupying the 
interstices, enveloping the pulp-elements ; and again the tissue-elements 
themselves appear to undergo calcareous degeneration. These all 
appear to be due to the occurrence of higher grades of pulp-disturb- 
ance and vascular reaction than represented in the case of orderly 
deposits of true dentinal substance. They probably arise in conse- 
quence of repeated hyperemia of low grades, of venous hyperemia, 
and of those conditions indefinitely known as chronic inflammations. 
Their association with these conditions, however, is not clear enough 
to definitely classify them as the consequences of any determined 
pathological condition of the pulp. While they are unquestionably 
evidences of pulp-degeneration, and should be so classified, they are, 
for the sake of convenience, grouped under the head of constructive 
changes. The fact that they are degenerations is to be constantly 
borne in mind. 

PULP-NODULES. 

Definition. — Pulp-nodules (pulp-stones, nodular calcifications) is the 
name applied to defined masses of calcic material occupying portions 

1 American System of Dentistry, vol. i. 



CONSTRUCTIVE DISEASES OF THE DENTAL PULP. 



335 



of the pulp-chamber and causing displacement of the pulp-sub- 
stance. 

Occurrence. — While these growths may occupy the pulp-chambers 
of teeth in which the pulp has been the seat of direct irritation, their 
occurrence is by no means confined to such teeth. They are found, not 
only in teeth which have suffered abrasion, erosion, and slowly progress- 
ing caries, but, as pointed out by Black, they may, and frequently do, 
form in other teeth of the same denture which are not directly involved 
in the irritation. This investigator notes that irritation of the pulp 
of one tooth of a denture very frequently causes a general hyperesthe- 
sia of the pulps of all of the teeth. This is particularly notable in the 
type of persons classed as neuralgic. It is also common in persons of 
the gouty diathesis. It should be remarked that a general pulp-hyper- 
sesthesia is frequently the precursor of an acute outbreak of gout in 
such persons. Nodules are found much more frequently in the teeth of 
middle-aged persons than in those of youth, although they may be pres- 
ent as early as the fifteenth year. They occur more frequently multiple 
than single. Some of the larger nodules are evidently formed by the 
coalescence of smaller ones. 

Pathology and Morbid Anatomy. — The structure of pulp-nodules 
does not resemble that of dentin ; they possess about the same degree 

Fig. 267. 




Section of a pulp-nodule, showing many calco-spherites, as pointed out by a, a. (Black.) 

of translucency and hardness. Outwardly they may assume almost any 
form ; they range in size from minute bodies to a size sufficient to 
almost obliterate the pulp (Fig. 265). 

A section of a nodule exhibits the presence of a number of concen- 
trically laminated bodies, recognizable as hardened calco-spherites. 
Black found them " to rarely make up any considerable portion of the 



336 



CONSTRUCTIVE DISEASES. 



bulk of the nodule. The remainder of the nodule is made up of struc- 
tureless dentinal matter. 

He also found deposits in the pulp which throw light upon the possible 
origin of nodules in some cases, and to some extent upon the conditions 
under which they may be formed (Fig. 268). In the pulp of a second 

Fig. 268. 




Deposit of calco-globulin within the tissues of an inflamed pulp. (Black.) 

molar of a girl aged fifteen, in which there had been decided subjective 
evidences of pulpitis recurring at intervals, for a period of two months, 
he found a mass representing a pulp-nodule in its soft state. "About 
one-half of the coronal portion of the pulp was involved in the inflam- 
mation ; lying a little inside of the layer of odontoblasts were several 
masses similar to Fig. 268, having globular forms in their mass or 
attached to their margins. The globular bodies present the laminated 
appearance of calco-spherites." These masses may in all probability 
be interpreted as intermediate products in the formation of nodules ; 
they have not yet become calcified. The conditions of calcification in 
enamel and dentin are not definitely known (Chapter VII.), so that the 
mode of calcification in pulp-nodules is also unknown. Black suggests, 
following the experiments of Rainey, Ord, and Harting, that the chemi- 
cal conditions for the formation of calco-spherites appear to be a solu- 
tion of albumin, calcium salts, and an excess of carbon dioxid ; these 
conditions are realized when there is an excess of venous blood in 
semi-stagnation, the conditions which exist in varicose veins, a patho- 
logical state in which concretions (phleboliths) appear in the veins. 
" When a venous thrombus is but partially replaced by connective 
tissue the remainder of it may become calcified, forming phleboliths. 1 
While this may and no doubt does serve to explain calcareous degen- 
erations, it fails to explain the formation of pulp-nodules, which exist 
in teeth which have never been the seat of caries, and whose pulps 
exhibit no structural change other than the presence of nodules. More- 
over, the presence of hardened calco-spherites, and even an amorphous 

1 Ziegler. 



CONSTRUCTIVE DISEASES OF THE DENTAL PULP. 337 

calcified, translucent mass, implies secretion rather than chemical pre- 
cipitation. They are, however, not to be classed as secondary dentin, be- 
cause they lack the distinguishing feature of dentin — dentinal tubules. 

Symptoms. — Multiple nodules may exist in a dental pulp and give 
rise to no evident symptoms whatever, as is shown by their presence in 
extracted teeth, many of them free from caries, and in which there 
was no history of pain. On the contrary, the pulp of a tooth may 
be the seat of intractable pain without a depth of carious invasion 
which would lead to the inference of acute pulp-disease ; and relief 
only be secured through devitalization of the pulp, which upon exami- 
nation may reveal a small pulp-nodule. 

The symptoms attendant upon the presence of nodules, so far as 
they can be made out, appear to be of two types — those associated with 
small and those with extensive deposits. Reflex pain is the common 
associate of both. 

Small Deposits. — While it is true that pulp-nodules exist in appar- 
ently sound teeth without inducing pain, yet the pulps of teeth contain- 
ing them become excessively hyperaBsthetic under what are ordinarily 
mild sources of irritation. This is manifested, first, through the con- 
tents of the dentinal tubuli ; the dentin becomes exquisitely sensitive, 
and cool water directed into a shallow cavity produces a paroxysmal 
and excruciatingly painful response from the pulp. In the absence of 
direct, extraneous irritation of the pulp, the dental symptoms may be 
absent, but a persistent neuralgia may be located at some distant point. 
Pain in the ear is a frequent symptom. Occasionally an obstinate scalp 
neuralgia, with the existence of a hypersesthetic spot, appears. Pain in 
the eye, with tenderness over the supra-orbital foramen, is also common. 
The pain may be recurrent or persistent. If, in the absence of a more 
probable explanation of the pain, a pulp-nodule be suspected, and 
arsenical applications be made to devitalize the pulp, it is found that 
not only is intense pain caused, but examination after from forty-eight 
to seventy-two hours shows the pulp to be still vital and hypersensitive ; 
and in order to effect its destruction repeated applications and large 
doses of arsenic must be used. 

Large Deposits. — In extensive deposits of pulp-nodules the dentin 
may be almost devoid of sensation, and applications of heat or cold, 
even in large cavities, may be followed by delayed and faint pulp- 
response. Such cases, however, commonly give a history of reflex neu- 
ralgia and vague dental pains extending over a period, it may be, of 
years. Their diagnosis may only be made after devitalization of 
the pulp and the finding of the nodules in the pulp-chamber or pulp- 
substance. The tardy action of arsenic is also observed in these cases, 
it being frequently necessary to devitalize the pulp piecemeal. 

22 



338 



CONSTRUCTIVE DISEASES. 



Treatment. — When pulp-nodules have been diagnosed as the 
probable source of dental pain or of reflex neuralgia, the therapeutic 
indication is the devitalization and removal of the pulp. The first 
arsenical application should contain a much greater amount of cocain 
than arsenic. In forty-eight hours a stronger paste may be applied. In 
the more obstinate cases, it may be one or two weeks before devitalization 
is complete. Uncomfortable symptoms referred to the teeth may persist 
for some time subsequent to devitalization and thorough removal of 
the pulp. Evidences of pericemental disturbance, tenderness upon per- 
cussion, may appear. The uncomfortable symptoms disappear, as a 
rule, if a saturated solution of menthol in chloroform be pumped in the 
canals, the cavity sealed, and the gum at a distance from the teeth be 
painted with tincture of iodin. 

CALCIFIC DEGENERATIONS OF THE PULP. 

Calcific degenerations of the pulp are of two types : one occurs 
as a sequel of the degenerative changes of age — atheroma ; the other, 
as calcic deposits in tissues of the pulp which have been the seat of 
acute or subacute vascular derangements. Calcareous degeneration, as 

Fig. 269. 










■*i -V; / - -Hi -k '.i[% ^ TmM 

X< t.ij -;c_> : .:■/■-..-■ •■•':■'■;>-... vV 




^4, diagram of a section of a central incisor, with a proximal decay at a which seems to have pene- 
trated the original pulp-chamber, but the opening is closed by calcification at b ; c marks the 
position of a detached mass of calcific material that was lost in mounting the section. B, 
shows the appearance of the calcific deposit ; this seems to be a calcification of inflamed or 
cicatricial tissue ; at a there is the appearance of a bloodvessel ; b, pulp. (Black.) 

pointed out in Chapter IV., has as a precursor other degenerative 
changes ; it is, in fact, a deposition of calcic material, calcium and mag- 
nesium phosphate and calcium carbonate, in already degenerated tissues. 
Causes. — The causes of calcareous degenerations of the pulp are 
therefore in previous diseases of the pulp which have induced degen- 






CONSTRUCTIVE DISEASES OF THE DENTAL PULP. 



339 



erative changes in the pulp-tissue. Prominent among these Black found 
grades of pulp-inflammation, of hyperemia (Fig. 269). 

Pathology and Morbid Anatomy. — The calcic material, unlike the 
cases of nodular calcification, incloses the anatomical elements of a pulp 
in process of degeneration in a mass produced by deposition, not secre- 
tion. In the root-portions of pulps in which fibrous elements have 
become pronounced the calcification may be tubular or cylindrical in 
character, the nature of the calcareous masses being apparently a depo- 
sition about and along the fibres (Fig. 270). 

Fig. 270. 




A, outline of a lower molar, with a large carious cavity at a; b, pulp-chamber ; the shaded portion, 
e, was occupied by cylindrical calcifications. B, cylindrical calcifications. (X 100.) (Black.) 



OSTEODENTIN. 

Tomes l states that secondary dentinal deposits may assume the 
character of osteodentin, a form of dentin found in the teeth of some 
animals, in which the tissue presents combined characters of both bone 
and dentin, citing the example also that elephant tusks are frequently 
repaired with osteodentin after injury. The specimen illustrated (Fig. 
271) was taken from a case in which the coronal portion of the pulp- 
chamber was almost obliterated by a deposit of secondary dentin. It is 
difficult to conceive the origin of the osteoblasts in this case ; the evi- 
dences of former odontoblasts are plain ; but whether odontoblasts under 
altered conditions have become osteoblasts is a matter of conjecture. 

To recapitulate, there appear to be at least three distinct types of 
calcic formations in the pulp-chamber. First, secondary dentin, in 
which the odontoblasts recede from their original positions in conse- 
quence of a new formation of dentinal material, leaving behind them 
processes which give the new formation the character of dentin. The 
process, in the main, is associated with a mild and continued irritation 
leading to a continued hypernutrition. After a period the physiological 
activity of the odontoblasts ceases and they undergo atrophy. The 

1 Dental Anatomy. 



340 



CONSTRUCTIVE DISEASES. 



second class of cases, nodular deposits, possess the physical and chem- 
ical properties of dentin without its anatomical characteristics ; it is 
dentinal substance, but not dentin histologically ; hence it differs from 
dentin in not being formed through the agency of odontoblasts ; it is 



Fig. 271 




Osteodentin: A, outline of incisor, showing a narrowing of the root-canal at 6 by a deposit of 
osteodentin. B, illustration of the tissue : a, primary dentin ; 'b, line of the beginning of a 
growth of secondary dentin ; c, secondary dentin ; d, layer of granular matter ; e, osteo- 
dentin ; this has the lacunae at g and dentinal tubes at k ; f seems to be the surface of the 
osseous deposit ; i, irregular crystalline deposits ; h, the pulp-chamber. X 350. (Black.) 

the product of secretory instead of formative action. Whether nodular 
deposits are first formed as a soft mass, and subsequently calcified, is 
not known. They appear in general to be the result of marked and 
irregular irritation of the pulp. The third form are calcareous depo- 
sitions about anatomically degenerated tissue occurring as a secondary 
process to degeneration and always indicating the near death of the 
pulp. 



CHAPTER XVIII. 

DESTRUCTIVE DISEASES OF THE DENTAL PULP. 

The next class of pulp-diseases are those of an acute character, 

although chronic diseases may arise as sequelae of the original conditions. 

They are essentially destructive in character and attended by prompt 

degeneration of the pulp-tissues. The most important clinically are 

those having an evident association with disorders of the bloodvessels 

of the pulp. 

Hyperemia of the Pulp. 

Hyperemia of the pulp is an excess of blood in the more or less 
dilated vessels of that organ. It is of two forms, active or arterial 
hyperemia, and venous or passive hyperemia or congestion. These 
two classes differ in their probable direct causations and in effects. 

ACTIVE HYPEREMIA OF THE PULP. 

Definition. — Active or arterial hyperemia of the pulp is an excess 
of blood in the dilated arteries and capillaries of the pulp. 

Causes. — The most common cause of active hyperemia of the pulp 
is a lessening of the non-conducting covering of the organ, enamel and 
dentin, leading to an increased response and continued irritation of the 
pulp through thermal stimuli. A similar condition consists in the 
presence of large metallic fillings in close proximity to the pulp, through 
which abnormal thermal stimuli are received. Fillings through which 
prompt pulp-response to thermal changes are felt are a direct menace 
to the continued health of the pulp. " The vigorous use of sandpaper 
disks in finishing large fillings may and does precipitate an attack of 
pulp hyperemia." x The loss of tooth-substance mentioned may be 
either through abrasion, erosion, or caries. The condition frequently 
occurs without direct exposure of the dental pulp. 

Symptoms. — When the pulp has lost much of its protective cover- 
ing, its response to thermal change becomes increased. So long as a 
quick, sharp pain is produced by contact with cold or hot substances, 
ceasing immediately, and only reappearing in response to direct stimuli, 
no serious vascular disturbance is inferred ; but when paroxysms of 
sharp pain lasting from many minutes to hours follow upon an applica- 
tion of cold to a carious cavity, an unbroken enamel-surface, a filling, 

1 Black. 

341 



342 DESTRUCTIVE DISEASES. 

or an area of erosion or abrasion, a disturbance of the vessels of the 
pulp is suspected. The pains, in the absence of direct and intentional 
irritation, are, as a rule, but vaguely located. It is common to have 
the pain referred to somewhere in the region of the affected tooth ; 
rarely to the tooth itself. It is not at all unusual to have the patient 
refer the pain to an entirely sound tooth at a distance from the one 
affected ; a tooth in the opposite jaw may be declared to be the seat of 
pain, and it may require the application of the thermal test to the 
offending pulp to convince the patient of the error of location. 

For some period previous to, and it may be after, an attack of acute 
paroxysmal pain, trigeminal neuralgia of the side may be complained of. 
A favorite location of this pain is in the ear. As a rule, when an upper 
tooth is affected the pain is located in the superior maxillary division of 
the fifth nerve ; if a lower, to the inferior maxillary division. The 
pain varies in intensity from a vague uneasiness to an acute neuralgic 
attack, with tender spots over the emergence of the nerve-tracks, at the 
supra- and infra-orbital, and mental foramina. The neuralgic pains are 
not always constant ; they may disappear from the second or third 
division of the fifth nerve and appear in the first. 

The proof of the direct connection between the pulp-pain and the 
neuralgia may in some cases be clearly made out by the thermal test. 
When a jet of cool water is directed against the tooth whose pulp is 
affected, it may produce, in addition to a local pain, an aggravation of 
the neuralgic pains. 

Pathology and Morbid Anatomy. — The one distinctive and charac- 
teristic anatomical condition associated with active hyperemia is an irreg- 
ular dilatation of the vessels of the pulp. 1 Fig. 272 represents a section 
of the pulp of a tooth extracted during a paroxysm of acute pain — 
" acute paroxysms of pain lasting for an hour or more were occasionally 
occurring in consequence of very trivial changes of temperature ; the 
condition had existed for several weeks." In some cases of a similar 
character — i. e., presenting the same symptoms, but extracted during an 
interval of quiet — nothing remarkable is presented ; the veins of the 
bulb may be abnormally large and contain more blood than usual, 
while the arteries will be almost or quite empty and the injection of 
the capillary system wanting ; that is, the affected arteries have recov- 
ered their calibre, if not their tone. Black found the varicose enlarge- 
ment of vessels so common (Fig. 273) as to be a characteristic. Salter 2 
first called attention to the dilatation of veins into ampulla?, describing 
them in connection with ulceration of the pulp, as due to engorgement 
and overtension of the veins. 

The most rational explanation of the dilatation of the vessels is that 

1 Black, American System of Dentistry. 2 Dental Pathology and Surgery. 



HYPEREMIA OF THE PULP. 



343 



it is an irregular paralysis of vessel-walls — i. e., of vasomotor nerves. 
Whether the more usual painful responses of the pulp to thermal stim- 




Hypersemia of the dental pulp, showing the natural injection of the vessels : a, a. membrana eboris, 
or layer of odonoblasts ; b, b, b, b, vessels distended with blood ; c, c, c, c, points from which the 
blood has fallen in handling the section. (Black.) 

uli are due to the stimulation of vasodilator fibres, which causes a transi- 
tory hyperaemia, is a matter of doubt ; but the pathological conditions 

Fig. 273, 




Dilated bloodvessels from the dental pulp in hyperemia, from tooth extracted during a paroxysm 

of intense pain. (Black.) 

noted in pronounced hyperemia signify a paralysis of vasoconstrictor 
fibres. Subjected to repeated over-stimulation, they become inactive 



344 DESTRUCTIVE DISEASES. 

and the vessel-walls yield to the pressure of the blood-column. Black's 
researches indicate that the vessel-walls may recover their tone and the 
vasoconstrictor nerves their functional activity after paralysis. 

Diagnosis and Prognosis. — Diagnosis of hyperemia of the pulp is 
made through observance of a combination of signs and symptoms. The 
symptoms leading to its detection are paroxysms of pain induced by 
thermal stimuli, and a history of pain in the region in which this re- 
sponse is elicited. The signs of the condition in the order of their 
importance and frequency are carious cavities, the presence of large 
metallic fillings, deep erosions or abrasions, and, again, fractured 
enamel exposing the dentin, or metallic crowns on teeth containing 
vital pulps. 

As a rule, the case presents a history of paroxysmal pain for a period ; 
either a single or several attacks. While, usually, pulp hyperemia 
is only associated with deep cavities of decay, it is occasionally found as 
an accompaniment of limited and comparatively superficial dentin 
exposures. The water used in testing the pulp-reaction should not be 
at a lower temperature than 60° F., and then be applied only in drops, 
never in a forcible stream. A normal pulp will rarely respond pain- 
fully to a few drops of water at the temperature named, flowed into a 
cavity ; but a hyperaemic pulp will almost invariably respond vigorously. 
As a rule, a current of air from a chip blower is a test of sufficient 
severity. 

In the absence of a carious cavity the source of the pain is to be 
sought in large fillings, testing each tooth by dropping cool water on 
the filling ; in cases of erosion or abrasion the test is made upon the 
exposed dentin. The tooth which responds in a quick paroxysm of 
intense pain, passing away slowly, is diagnosed as the seat of pulp 
hyperemia. 

The prognosis of this condition is important as determining the course 
of treatment. Governed by clinical experience, many operators invari- 
ably devitalize and remove a pulp which has been the seat of more than 
one attack of paroxysmal pain. Others attempt the conservative treat- 
ment of the organ even when it has been judged from the symptoms 
the seat of repeated hyperemia, and report that success usually attends 
the effort, provided due precautions have been taken as to antisepsis, 
the character of pulp-cupping, and to non-conductivity of the pulp- 
covering. 

Black l has show^n the capability of the pulp to recover from repeated 
hyperemia ; that is,, as regards the condition of its bloodvessels ; and 
the records of observers (notably Louis Jack 2 ) show that after years 

1 American System of Dentistry, vol. i. 



2 



American Text-book of Operative Dentistry. 



HYPEREMIA OF THE PULP. 345 

the pulp responds normally to thermal stimuli, proving its continued 
vitality, aye more, its health. It is possible that those who condemn 
the attempts at conservation of the pulp after hyperemia have con- 
founded this vascular condition with serious degenerative changes. 
Properly treated, the prognosis of active hyperemia of the pulp is, 
upon the whole, favorable. 

Treatment. — The therapeutic principles involved in the treatment 
of this condition are : the removal of the source of irritation and the 
securing of physiological rest ; the latter can only be secured through 
the removal of the former. The treatment is directed toward imme- 
diate relief of the existing condition and the prevention of its re-occur- 
rence. If a carious cavity exist, it is to be freed from debris ; and the 
grosser portions of the carious dentin are removed ; the pulp, if unex- 
posed, is to have the layer of softened dentin covering it left unremoved. 
Sedative agents are imperatively called for, that most commonly em- 
ployed being carbolic acid. This agent is, however, discountenanced 
by some practitioners on account of the possible deleterious effect it 
may have on the pulp ; this objection is not generally sustained. The 
essential oils are perhaps the most effective agents for use in this con- 
nection. The oils of cloves, of gaultheria, cinnamon, thyme, and 
menthol are all extensively used and are all effective. Of these, thymol 
acts most promptly ; a saturated solution in alcohol being used, sealed 
in the cavity with temporary stopping. It is, in addition, a germicide 
of sufficient activity to sterilize the dentin covering the pulp. The 
essential oils act as sedatives, and the non-conducting temporary stopping 
secures rest by preventing the conduction of thermal stimuli. In from 
twenty -four to forty-eight hours the tooth is placed under the rubber-dam, 
and excavated (see Chapter XVI.); its walls are varnished, and over 
the wall nearest the pulp a disk of softened gutta-percha is laid. Over 
this zinc-phosphate paste is flowed. It is usual to complete such fillings 
with zinc phosphate or gutta-percha, to remain for six months or a year. 
The conductivity of zinc phosphate is too high to be used as the sole 
material over pulps which have been the seat of hyperemia. If the 
pulp be exposed, it is capped as described in Chapter XVI. 

In cases of abrasion or erosion carbolic acid is applied ; an excava- 
tion having a retentive form is made, which is varnished and filled with 
zinc phosphate. A tooth containing a large metallic filling must have 
the filling removed and after reducing the hyperemia a non-conducting 
layer must be placed between the pulp and the filling. The precaution 
should always be taken, when the pulps of teeth in which cavities have 
been prepared respond unduly to the temperature-test, to cover the 
dentinal walls with a layer of non-conducting material. In the absence 
of this precaution the constant overstimulation of the pulp by thermal 



346 



DESTR UCTIVE DISEASES. 



impulses conducted through the metallic filling,- may at any time result 
in hyperemia. 

Idiopathic hyperemia occasionally affects teeth in which there is no 
loss of enamel or dentin ; and when this condition occurs, it leads to 
suspicion that the pulp is the seat of nodular deposits. Such teeth are 
to be dried, heavily varnished, and wedged upon both sides for twenty- 
four hours, until a gutta-percha cap can be fitted to them completely 
enclosing the crown. The cap is to remain and to be renewed until the 
tooth responds normally to the temperature-test. 

VENOUS HYPEREMIA OF THE PULP. 

Pathology and Morbid Anatomy. — Considering the mode of vas- 
cular supply to the teeth, arteries entering and veins leaving the tooth 
by a rigid and constricted channel, it is evident that if the arteries be 
dilated the veins must suffer more or less compression, causing a 

Fig. 274. 



*M 




Section of hypersemic pulp, showing aneurismal dilatation of the vessels, extravasations of blood, 
and red blood-disks escaped apparently by diapedesis : a, a, dilated vessels ; &, b, b, extrava- 
sated blood. Besides this, red blood-disks are plentifully distributed everywhere in the 
neighborhood of the veins. The tooth was extracted diiring a paroxysm of pain. (Black.) 



mechanical obstruction to the return of the blood — i. e., venous or 
mechanical congestion is likely to be established. 

In teeth having more than one root the venous engorgement may be 



HYPEREMIA OF THE PULP. 347 

lessened by escape of blood through a second root. In single-rooted 
teeth congestion must be established when the artery or arteries are 
affected near the apical foramen. It is inferred that in the foregoing 
conditions described the interference with venous return has been but 
partial. 

The condition raises the tension of the blood in the capillaries and 
minute veins, and produces stagnation in the emergent veins ; there is 
mechanical stagnation (Fig. 274). It is evident that if this condition 
continue for a length of time that thrombosis must occur in one or 
more veins. 

Black l has described sequela? of active hyperemia which appear to 
correspond with those conditions. Extravasations of red blood-cor- 
puscles occur in the tissues. (Edema, the usual accompaniment of 
venous congestion, cannot occur, as there is no room for exudations. 
The condition, corpuscular extravasation, corresponds with that of 
hemorrhagic infarct — the degeneration and death of more or less pulp- 
tissue are inevitable. Black suggests that, no doubt, many cases of 
pulp death en masse are due to the condition of general infarction. 
The force of this suggestion is evident when it is remembered that the 
arteries to single-rooted teeth are virtually terminal arteries. If the 
infarction be incomplete, more or less inflammation of the pulp is 
almost sure to supervene. Disintegration of the red corpuscles may 
occur and the coloring-matter of the corpuscles may be diffused through 
the dentin, giving it a pink discoloration. The infiltrated dentin may 
then become progressively discolored through the characteristic changes 
of Color noted in connection with gradually decomposing haemoglobin — 
becoming brown, blue, and finally blue-black. 

Symptoms. — The symptoms of this condition, in the absence of 
definite data, can only be inferential. When the paroxysms of pain 
are continuous, instead of temporary — that is, when the pain, instead 
of temporarily subsiding, maintains a constant intensity for hours, and 
does not respond promptly to therapeusis, and is accompanied by a sense 
of fulness rather than sharp agony, a condition of serious venous con- 
gestion is inferred. The case from which the illustration is taken had 
been the seat of intense paroxysmal pain for some hours. 

Prognosis. — Perfect recovery from this condition is extremely 
doubtful, so that if the pulp be not intentionally devitalized and 
removed, it will undergo degenerative changes. The fact that pulps 
have remained alive for years, after having been the seat of marked 
congestion, scarcely warrants the attempt to save so seriously crippled 
an organ in all cases. 

Treatment. — Considering the nature of the anatomical changes, it is 
1 American System of Dentistry, vol. i. 



348 DESTRUCTIVE DISEASES. 

doubtful whether the pulp can ever fully recover ; so that devitalization and 
extirpation are usually practised in these cases. Before this is attempted 
or before any attempt is made at permanent treatment, relief is demanded 
from the pain. After washing out the cavity with warm alkaline solu- 
tions, a warm solution of phenol sodique is admirable ; the cavity is 
cleansed of softened dentin, usually exposing the pulp in the operation. 
This organ, instead of being pink, is seen to have a purplish hue, and 
immediately protrudes through the opening of exposure. If the surface 
of the pulp and the cavity-walls be touched with a strong antiseptic, 
such as a solution of hydro naphthol in alcohol, and a very sharp probe 
which has been dipped in carbolic acid be used to delicately punc- 
ture the pulp, there is an immediate and free flow of blood which is 
permitted to continue for some minutes, relieving the vascular engorge- 
ment. In five minutes the cavity is syringed with a warm antiseptic 
solution (phenol sodique will answer), and a pellet of cotton containing a 
saturated solution of menthol in chloroform may be laid over the pulp, and 
retained in place by another pellet of cotton. This application is usually 
more effective than even a saturated solution of cocain hydrochlorid in 
glycerin. The following day an arsenical application may be made. 
If the pain subside, and the pulp remain quiet for a week under a 
temporary stopping, some operators have advocated pulp-capping even 
in this condition. 

Inflammation of the Dental Pulp, or Pulpitis. 

Definition. — Inflammation, as pointed out in Chapter IV., is a pro- 
cess to be sharply differentiated from that of hyperemia. It is entirely 
separate and distinct. While several of the phenomena of arterial 
hyperemia are present in inflammation, they constitute but a part of the 
process. The essential feature of inflammation is the peculiar aggrega- 
tion and diapedesis of the white blood-corpuscles. Hyperemia, no 
matter of what grade or variety, rarely exhibits this feature, and then 
but slightly, nor in any degree does it present the same types of exuda- 
tion or of tissue-change observed in inflammation. Inflammation of 
the dental pulp is a condition in which the phenomena of the inflam- 
matory process (see Chapter IV.) occur in the dental pulp, their course 
being modified, as in many other tissues of the body, by the peculiar 
anatomical surroundings. 

Causes. — Nowhere more than in the dental pulp does the force of 
Metehnikoff 7 s dictum, that all inflammations are bacterial in origin, 
seem to apply. While it must be admitted that here as elsewhere the 
vast majority of inflammations are bacterial in origin, and that the 
theory of phagocytosis is the most inclusive that has yet been offered, 
yet there are numerous conditions in which the bacterial origin has not 



INFLAMMATION OF THE DENTAL PULP, OR PULPITIS. 349 

been made out. We may accept, however, that inflammation is essen- 
tially Nature's method of ridding herself of irritants, and that phago- 
cytosis is the mechanism through which this is accomplished, and leave 
the question of the necessary association of bacteria sub judice. 

Taking this position, inflammations of the dental pulp may be divided 
into infective and non-infective. There are in all probability other 
irritant factors, in addition to those causing hyperemia, necessary before 
inflammation can result. The irritants relate to injuries either through 
the operation of physical forces or chemical agencies. The chief of the 
physical forces is the presence of foreign bodies, either upon the surface 
of the pulp or in its substance. The chemical bodies are those which 
cause death of the tissues of the pulp, the inflammation being a reaction 
representing an attempt of the pulp to segregate or expel the dead 
tissue ; or those chemical bodies produced by bacteria which attract the 
white blood-corpuscles (positive chemotaxis). 

Pulpitis is classified, according to its extent, into partial and com- 
plete ; according to its duration, into acute and chronic ; according to its 
infective character, into purulent and non-purulent ; and, again, according 
to the character of the degeneration which follows upon the inflammatory 
process. While pathologically these conditions may be clearly dif- 
ferentiated from one another, they may be reduced to more compact 
groupings according to their clinical significance. For example, acute 
pulpitis is frequently infective, partial and purulent ; chronic pulpitis 
is frequently non-infective, extensive, non-purulent, and indicative of 
secondary degenerations. 

For the sake of convenience, pulpitis will receive a clinical division 
into acute and chronic. Some of the chronic varieties have been de- 
scribed under the head of degenerations ; others are included in the 
suppurative diseases of the pulp. 

ACUTE PULPITIS. 

Causes. — The causes of acute pulpitis are direct and indirect, intrin- 
sic and extrinsic ; the vast majority of cases being due to extrinsic 
causes. The direct intrinsic causes are hemorrhagic extravasations ac- 
companying venous congestion, pulp-nodules, and injury of the vessels 
at the apex of the root. The direct extrinsic causes are, perhaps, invari- 
ably associated with bacterial invasion, a possible exception being the 
pressure of filling-material upon a thin elastic lamina of softened 
dentin, covering the pulp. The dental pulp is intolerant of the slight- 
est pressure, and rebels vigorously when subjected to compression. It 
is not necessary l that the pulp should be exposed to permit bacterial 
infection, and direct or extensive bacterial invasion is probably not 

1 Miller, Dental Cosmos, 1894. 



350 



DESTRUCTIVE DISEASES. 



necessary for the production of pulpitis. The waste-products, pto- 
mains, etc., of bacteria may find their way to the surface of the pulp 
via the dentinal tubuli, through a layer of softened dentin, and excite 
inflammation. It is extremely probable that infection of the pulp 
is an invariable consequence of its exposure ; but as a pulp may be 
exposed without subjective evidences of hyperemia or inflammation, it 
follows that infection does not necessarily imply inflammation. The 
presence of a gross irritant, such as a mass of food-debris, vegetable 
seeds, bread-crumbs, etc., in contact with the pulp will precipitate an 
acute inflammation in which bacterial relations must be taken into 
consideration. 

" The severity of the inflammation does not appear to be proportion- 
ate to the number of bacteria present, and in a highly inflamed pulp 
we may be able to find but few bacteria. . . . The conclusion seems to 
be justified that the inflammation is due to the combined action of the 
bacteria and their products (acids, ptoma'ins, etc.) with which the carious 
dentin becomes impregnated." 1 

The general indirect intrinsic cause of pulp-inflammation may be 
regarded as active hyperemia. This condition furnishes a predisposi- 
tion to active inflammation, as shown in Chapter V. Pulpitis frequently 
occurs as a sequel to active hyperemia, and the causes producing this 
condition must, therefore, be also regarded as the causes of inflamma- 

Fig. 275. 




Inflammation of dental pulp : a, a, normal cells ; b, b, b, b, inflammatory elements ; c, cells in 

process of division (^ in.)- (Black.) 



tion. The use of irritating drugs in proximity to or in contact with the 
pulp may excite inflammation. 

Morbid Anatomy and Pathology. — In determining the existence 
of pulpitis, no matter what the symptoms which have presented or the 

1 Miller, Dental Cosmos, 1894. 



INFLAMMATION OF THE DENTAL PULP, OR PULPITIS. 351 

condition as to exposure, etc., the microscopic examination of sections 
of the affected organ constitutes the only test ; if the changes character- 
istic of inflammation be absent, no matter what the symptoms, pulpitis 
did not exist. The essential feature of the process is emigration of 
the white blood-corpuscles from the small veins into the intercellular 
matrix of the pulp. At first the inflammatory elements (leucocytes) 
are scattered through the spaces between the pulp-cells (Fig. 275) ; 

Fig. 276. 




Section of dental pulp, showing the invasion of the inflammatory process along the course of the 
veins— the diapedesis of the white blood-corpuscles. (Black.) 

at a later stage the territory is occupied by round indifferent cells alone. 
The inflammation may be widespread, as shown in Fig. 276, or may 

Fig. 277. 




Minute inflammatory focus within the tissues of the pulp : o, a, arterial twigs : b, a nerve-bundle ; 

c, collection of leucocytes. (Black.) 

be localized to some portion of the pulp, as one horn of a pulp ; Black 
noted also inflammatory action occurring in small islands (Fig. 277). 
Swelling of the pulp — exudation — cannot occur unless there is a 



352 DESTRUCTIVE DISEASES. 

break in the wall of the pulp-chamber through which additional space 
can be gained. Black has recorded that " he found beneath the layer 
of odontoblasts in the region of an exposure an unmistakable deposit 
of inflammatory lymph. The case had a history of severe toothache 
for two days, two weeks previously. The pulp exhibited evidences of 
previous extravasations of blood from hyperemia." 

There is evidence that the pulp may recover from attacks of inflam- 
mation, and that resolution occurs. In some cases, as shown under the 
head of calcareous degeneration, the tissues may become infiltrated with 
calcic material. In others, chronic degenerative changes — inflammatory 
degeneration — may supervene. 

The cases thus far described have been given as non-infective, simply 
because their infective character has not been clearly made out, although 
it is very probable that they are infective. 

Suppuration of the pulp is a common accompaniment of pulp-inflam- 
mation ; this being necessarily infective, will be described separately. 

Symptoms. — The symptoms of pulpitis are largely a matter of 
inference. The existence of hyperemia and a general paretic state of 
the bloodvessels are judged by symptoms. Throbbing pain referred to 
the region of some one tooth, and at times referred definitely to the 
affected tooth, is regarded as a guiding symptom. The tooth may 
respond to percussion slightly. The pericementum being involved to 
some extent, the throbbing attendant upon the pulpitis is the reason for 
the pain being located at times in the offending tooth, instead of being 
reflected, as usual in pulp-affections. In other cases the pain is referred 
to far distant points in the course, or at points, of any of the divisions 
of the fifth nerve. No pain may be felt in the tooth at all, and serious 
disturbances appear in distant parts, in the eye or ear. The usual symp- 
tom, however, in addition to the heavy, throbbing pain in the tooth, is a 
marked increase of suffering upon assuming the recumbent position. 
The paretic vessels permit an increased flow of blood into them as 
soon as its flow to the tooth is favored by gravity. In the upright 
position during the day the suffering continues, although lessened, as a 
dull, heavy pain. The pulp responds to both heat and cold, but more to 
the former than to the latter. 

Diagnosis. — Inflammation of the pulp is the usual associate of 
exposure of the organ whether marked symptoms have been present or 
not. Its actual existence is judged from presenting the local symptoms 
noted. A large cavity, with an exposed pulp, with dull, heavy pain, 
increased in the recumbent position, with little or no response to per- 
cussion — pulpitis is diagnosed. If in a tooth containing a large filling 
these symptoms have been present, pulpitis is inferred. 

Pulpitis from injury of the vessels at the apex of the root must be 



INFLAMMATION OF THE DENTAL PULP, OR PULPITIS. 353 

mentioned. It may occur in consequence of blows, biting upon hard 
substances, too rapid wedging, the rapid movement of teeth in ortho- 
dontia, and the progressive loosening of teeth in pyorrhoea alveolaris. 
In these cases the pericementum is also affected and the teeth are tender 
upon percussion. Pain in the teeth upon assuming the recumbent posi- 
tion, dull, heavy uneasiness about the jaws, and inordinate response 
to thermal stimuli, particularly to heat, point to pulpitis. No doubt 
many pulps are destroyed by general hemorrhagic infarct in these 
cases. 

Prognosis. — While it is undoubtedly true that the pulps of teeth 
which have been the seat of inflammation may recover, that resolution 
may occur, it is the general experience that they usually degenerate and 
die ; if attempts are made at conservation, supplementary pathological 
changes occur which result in the death and decomposition of the 
organ. Months or years afterward the tooth increases in opacity, and 
if the pulp-chamber be opened, the pulp is seen to have undergone 
decomposition. 

Treatment. — Pulpitis when fully established is at times very obdu- 
rate so far as local therapeusis is concerned. The same local measures 
apply as in venous hyperemia, local bloodletting when feasible, and 
applications of obtundents and sedatives. Of all local agents, none 
appears to furnish a greater measure of relief than applications of a paste 
of cocain hydrochlorid in glycerin, although saturated solutions of menthol 
and thymol are both effective. Atropia sulfate, gr. j-^j, is also markedly 
sedative. These applications should be sealed in the tooth by means 
of temporary stopping, being careful that no pressure is made upon the 
pulp or it will respond vigorously. 

Before making any medicinal applications to the exposed pulp the 
cavity should be freely and repeatedly syringed with warm antiseptic 
solutions, a 50 per cent, solution of meditrina answers well. Coagulant 
agents are not used, as the coagulum formed interferes with the action 
of other remedies. If the tooth contain a large filling, it is removed, 
at least in part, until access to or proximity to the pulp is attained. 

The measures stated will afford partial but not complete relief; gen- 
eral antiphlogistic measures are indicated. Of these, perhaps the most 
effective is local bloodletting. 

Nancrede's experiments 1 have shown that one of the most effective 

methods of unloading an area of engorgement, is to take away blood, 

and establish a rapid flow through veins adjacent to the area. Making a 

few cuts with a sharp lancet in the gum overlying the root of the affected 

tooth, and promoting the flow of blood by holding warm water in the 

mouth, is a useful measure. 

1 Warren' s Surgical Pathology and Therapeutics. 
23 



354 



DESTRUCTIVE DISEASES. 



Carefully drying the gum and painting over a small area canthar- 
idal collodion and forming a blister is a useful means of derivation. 

The continued application of a pepper bag to the gum, and painting 
the gum with tincture of iodin, both tend to unload the engorged pulp ; 
but none of them has so pronounced effect as direct local bloodletting. 
If the patient's repugnance to the operation can be overcome, leeching 
is an effective means of relief. The gum is scrubbed clean, the leech 
being very loath to attach itself to a dirty surface, and touched with a solu- 
tion of sugar. The (Swedish) leech, enclosed in a small test-tube, is to be 
brought to work, by having the tube-mouth pressed upon the gum. As 
soon as the leech is engorged, the tube is withdrawn slightly and salt 
(sodium chlorid) is dropped upon the animal, which then falls back into 
the test-tube. 

The administration at night of ammonol, grs. x, in addition to local 
sedatives and local bloodletting, will usually secure quiet. If the pa- 
tient be at all costive, a dose of Epsom salt, magnesium sulfate, a 
tablespoonful in a goblet of water, is an additional means of relief. 
Quiet of the pulp must be secured before an arsenical application is 
made, or the latter merely increases the irritation instead of promptly 
devitalizing. 



Fig. 278. 



Suppuration of the Pulp. 

Definition. — By suppuration of the dental pulp is meant a forma- 
tion of pus on its surface (ulceration) or in 
its substance (abscesses). It occurs both as 
an acute and as a chronic affection. 

Causes. — The immediate cause of sup- 
puration of the pulp is the ingress of pyo- 
genic organisms to the pulp. As in inflam- 
mation of the pulp, while usually associated 
with direct exposure of the pulp, suppura- 
tion may occur in pulps covered by softened, 
or even unsoftened dentin. 1 " Bacteria 
which have entered the body through 
wounds may be deposited in the pulp as 
well as in any other part of the body, wher- 
ever there may be a locus minoris resistentice at the time. 

Arkovy 2 (Fig. 278) first observed infection of the pulp while still 
covered by a layer of unsoftened dentin. Miller 3 questions whether 
bacteria can pass through any but very thin layers of dentin. He 
states 4 that sections of the overlying dentin in a case of suppuration of 




Invasion of pulp by micrococci. 

(Arkovy.) 



1 Miller, Dental Cosmos, 1894. 

3 Micro-organisms of the Human Mouth. 



2 Diagnostik der Zahnkrankheiten. 
4 Dental Cosmos, 1894. 



SUPPURATION OF THE PULP. 



355 



the pulp showed the same forms of bacteria as were found in the pulp 
itself. 

In cases where suppuration has occurred in teeth containing large 
fillings which are perfect and intact, and the pulp has never been 
exposed, it is a reasonable inference that the organisms necessary to 
pus-formation have found their way to the dental pulp via the general 
circulation. This infection in purulent pulpitis is a mixed one, both 
cocci and bacilli being present, and in later stages of degeneration 
other forms appear also. 

Suppuration of the pulp is a not infrequent sequel of the capping 
of pulps which had given evidence of a previous hyperemia or inflam- 
mation. 

Morbid Anatomy and Pathology. — Anatomically pulp suppura- 
tion, purulent or pyogenic pulpitis, is of two general varieties ; one 
begins upon or close to the surface of an exposed pulp, and gradually 
destroys the organ through a process of progressive (Fig. 279) ulcera- 

Fig. 279. 




diagram of lower molar, with caries at a which exposes the pulp ; the darkened portion at b 
shows the extent of the inflammation ; the rest of the organ was free from inflammatory 
change. B, illustration of the inflamed tissue, showing a part destroyed by suppuration at a ; 
the odontoblasts are undermined at b; the bloodvessels which were filled with blood-clot in 
the section are left blank here, that they may be more apparent. (Black.) 



tion ; the second, that confined in the substance of the pulp, causes 
the gradual destruction of a part or all of the pulp through the forma- 
tion of circumscribed abscesses (Fig. 280). 



356 



DESTRUCTIVE DISEASES. 



Fig. 280. 







Acute suppurative pulpitis in the coronal portion : I, intensely inflamed horn ; A, abscess ; V, blood- 
vessels engorged with blood ; S, superficially inflamed horn ; N, nest of inflammation. X 10. 
(Bodecker.) 

Ulceration of the Pulp. 

Of these two forms, ulceration is the more common. The capillaries 
(Fig. 279) are blocked with coagulated blood (they are left open 
in the illustration to clearly mark their position) ; the intercapil- 
lary meshwork is occupied by inflammatory exudation ; the surface of 
the pulp is eroded, and covered with pus-corpuscles ; the ulcerative 
process is undermining the layer of odontoblasts. The suppurative 
process penetrates the body of the pulp, following the direction of its 
veins and hollowing out the organ into a deep cavern. Black regards 



ABSCESS OF THE PULP. 



357 



the persistence of the layer of odontoblasts as indicating an inferior 
vitality, as it shows they are less susceptible of change of form than 
the other cells of the organ. 

The process of ulceration may continue for weeks or months until 
the entire organ has been destroyed molecularly. The necrotic por- 
tions undergo putrefactive decomposition, probably passing through 
the same stages that any albuminous substance passes in its serial 
decomposition, into the end-products — ammonia, carbon dioxid, hydro- 
gen sulfid, and water. 

"Very interesting and instructive results were obtained by examining 
material from different parts of the same tooth. In the case illustrated 
in Fig. 281 the pulp-chamber at a was Avide open and filled with 
food-particles, which had a foul, half-putrid odor ; at b the pulp was 
putrid and foul-smelling ; at c there was a small abscess, filled with 
pure white pus, while the tissue between this point and the apex of the 
root was highly inflamed and bright red. Material from the pulp- 
chamber (<x, Fig. 281) contained the forms shown in Fig. 282 ; material 
from point b those shown in Fig. 283, and from the point c those shown 
in Fig. 284. We perceive a gradual diminution of the large cocci, and 
the appearance of small, delicate cocci and diplococci " (Miller). 1 



Fig. 281. 



Fig. 282. 



Fig. 283. 




Fig. 284. 











Fig. 285. 



•V - 



-* 



Micro-organisms found in cultures from a gangrenous pulp. 



Abscess op the Pulp. 

Abscess of the pulp is usually situated near the point of exposure 
of the organ. It may be confined to one horn of the pulp, or may 

1 Dental Cosmos, 1894. 



358 



DESTRUCTIVE DISEASES. 



involve nearly the entire substance of the pulp, the peripheral tissue 
of the pulp beiug unbroken. Abscess may exist at some distance 
beneath the surface of the pulp, and the latter be still covered with 
a layer of dentin. The writer once uncovered the horn of a molar pulp 
which was covered by a lamina of hard dentin, and no fluid appeared ; 
but upon passing a sharp probe into the white area of exposure for over 
one-eighth of an inch or more there was a free flow of pus which quickly 
filled the larger carious cavity. A pulp removed entire from a tooth 
which was yellowish-white in color and unbroken showed upon sec- 
tion its interior hollowed out into an enormous abscess-cavity (Fig. 
286). The bloodvessels were blocked ; the peripheral tissues were unal- 

Fig. 286. 




a be 

Transverse section of inferior bicuspid pulp, one-half diagrammatic : a, abscess-cavity ; b, embry- 
onic cells at the periphery of abscess-cavity ; c, occluded bloodvessels. 

tered ; between the odontoblasts and the abscess-cavity, the latter lined 
with pus-corpuscles, evidences of inflammation were plenty. Black 
found that the odontoblasts retained their form after neighboring cells 
of the pulp had been destroyed. 

Miller's 1 researches show a preponderance of cocci and micrococci 
in cases of enclosed abscess ; cocci and diplococci were of constant occur- 
rence. Many of the forms, both cocci and bacilli, were cultivable upon 
gelatin and agar-agar. Some of them, cocci and bacilli, brought about 
the liquefaction of gelatin ; others did not. So that it must be inferred 
that infective inflammation and necrosis of the pulp may occur without 
suppuration. In some instances streptococci were found. In the freely 
exposed pulps varieties of organisms were found which would render 
clear the possibility of a general infection by way of the dental pulp. 

1 Dental Cosmos, 1894. 



ABSCESS OF THE PULP. 359 

Symptoms. — Many cases of ulcerative suppuration of the pulp 
may run their course to complete or almost complete destruction of 
the organ, and no uneasiness arise until septic pericementitis appears, 
which it almost invariably does some time subsequent to death of the 
pulp. In other cases, however, pains characteristic of inflammation 
of the pulp are noted, but response to the cold test has almost dis- 
appeared. Intense pain may exist when the pus does not find ready 
exit owing to food-debris being massed in the cavity of decay or to the 
presence of a large filling. The condition then resembles that of abscess 
of the pulp. The usual history of the latter disease is as follows ; in 
a tooth containing an enormous filling, one in which the pulp has been 
exposed, or in a tooth having a large carious cavity, the patient gives 
a history of discomfort or decided pain, appearing at intervals ; the 
existing condition having been ushered in by dull, gnawing pain, which 
is usually not positively located, although it may be. The pain grows in 
intensity, and, in contradistinction to the pulp-conditions previously de- 
scribed, pain is relieved instead of increased by applications of cold. It 
may be, however, that the prolonged contact of ice-water may induce 
a response. The response to heat is marked, so that a mouthful of hot 
coffee may precipitate an attack of severe and continued pain. If the 
pulp be freely exposed and pricked with a sharp instrument, a flow 
of pus follows in many cases, and the relief is almost immediate. In 
the earlier stages a period of throbbing pain may follow evacuation of 
the pus. 

In other cases the response to heat may decrease until it is almost 
absent, and the case only be seen when evidences of the action of bac- 
terial products upon the pericementum appear, which they usually do 
in the later stages of pulp suppuration ; when the tooth becomes loose, 
extruded, and tender upon percussion. If untreated, symptoms of pulp 
and pericemental disturbance may disappear for weeks or months ; but 
if the parts be not perfectly sterilized and reinfection prevented, it is 
only a question of time when septic pericementitis will arise. 

Diagnosis. — The most valuable diagnostic sign is the peculiar reac- 
tion to thermal stimuli — the decreasing, then absent response to cold, and 
the increasing reaction to applications of heat. This reaction, together 
with the continued gnawing, and full sensation in the tooth, usually 
affords, a diagnosis, which is confirmed by evacuating pus from the pulp. 

Prognosis. — General experience regards ulceration and abscess of 
the pulp as precursors of the death of the organ. Usually this is by 
progressive suppuration. It is undoubtedly true, however, that at- 
tempts at circumvallation of the dead tissue are made in some cases 
(Fig. 287). The pus-cells undergo degeneration and the abscess-site 
may be the seat of calcareous deposits. Even in these cases death is 



360 



DESTRUCTIVE DISEASES. 



delayed, not averted. The remainder of the pulp undergoes atrophic 
changes, and commonly suppuration reappears. 

Treatment. — The treatment of the case consists in relieving the 
existing pain, completing the devitalization of the pulp, and removing 



Fig. 287. 




Chronic suppurative pulpitis terminating in calcification of the pus and atrophy of the pulps. 
a 1 , larger abscess, filled with calcified pus ; a 2 , abscess at the periphery of the pulp ; a 3 , a 3 , small 
longitudinal abscesses, all calcified ; N, calcified nerve-bundle ; c, c, calcareous depositions 
in the fibrous pulp-tissue ; p, p, pigment-clusters from previous hemorrhage. X 10. (Bodecker.) 

it in such a manner that no organisms or dead matter are carried beyond 
the apex of the root. 

To secure relief, evacuation of the pus is imperatively necessary. 
The organ is freely exposed, exercising no pressure in gaining free access 
to it. If pus do not flow upon exposure of the surface of the pulp, the 



ABSCESS OF THE PULP. 361 

cavity and pulp, the tooth being under rubber-dam, are drenched with 
strong antiseptics — a spray of hydrogen dioxid or of meditrina — and a 
sharp, slender sterilized probe is quickly passed into the substance of 
the pulp, when if pus be present it will usually escape freely through 
the opening thus made. 

If the pus-formation be limited and circumscribed, throbbing pain 
may follow, which promptly quiets under an application of cocain in 
glycerin. The application is not made until the pus-flow ceases. A 
pellet of cotton wet with a 3 per cent, solution of formalin, or a satu- 
rated solution of thymol, is laid upon the pulp and the cavity is sealed 
for twenty-four hours (never longer), and then an arsenical application 
is made. Should the exposed portion of the pulp be insensitive it is 
burred away until access is had to the vital portion, where the arsenic is 
to be applied. Antiseptics are to be freely used, and the rubber-dam 
applied before entrance to the pulp for any therapeutic applications. 



CHAPTER XIX. 

CHRONIC DEGENERATIONS AND DEVITALIZATION OF THE 

PULP. 

Some of the chronic degenerations of the pulp have been described 
under the head of secondary deposits in the pulp-substance. The 
grades of hyperemia, active inflammation and suppuration represent 
the acute degenerations of the organ. 

Chronic Inflammation. 

As stated in Chapter XVIII. , ulceration of the pulp commonly 
pursues a chronic and progressive course until the organ is destroyed ; the 
condition may, therefore, be termed chronic purulent pulpitis (ulcerosa), 
as an inflammatory zone lies beyond the line of suppuration. This con- 
dition has already been discussed. 

Abscess of the pulp may pursue a chronic course, as stated. Attempts 
are occasionally seen at repair in the affected pulp, the abscess-area 
being marked off, and the elements contained in it becoming the seat 
of calcareous deposits. 

sclerosis of the pulp. 

Inflammation of a low grade may persist in the pulp for long periods, 
giving rise to an increase of its fibrous tissue with atrophy of the 
pulp-elements, producing a condition similar to that found in chronic 
interstitial inflammation in some other tissues — a sclerosis. Instead of 
the usual distribution of myxomatous tissue, bands and bundles of 
fibrous tissue appear. The pulp appears shrunken and stiff, bloodvessels 
are contracted, and the nerve-fibres have undergone partial or complete 
atrophy. 

Black l found that in the late stages of sclerotic atrophy areolae 
developed in the bundles of connective tissue, the inflammatory elements 
having disappeared, and the areolae being occupied by fluid. Arkovy 
describes this condition as reticular atrophy of the pulp (Fig. 288). 
The condition would point, as suggested by Black, rather to venous 
hyperaemia as the cause of the oedema than to inflammation ; but the 
evidences of former chronic inflammation in the existence of the bundles 
of reticulated tissue show this to have been the essential condition. The 

1 American System of Dentistry, vol. i. 
362 



CHR ONIC INFLAMMA TION. 



363 



observations of the same writer indicate that atrophy of the odontoblasts 
is a usual accompaniment of all of the chronic pulp affections. 

Sclerotic and other chronic degenerations of the pulp usually pre- 
sent the history of one or more attacks of pulpitis in the past, with 

Fm. 288. 




Chronic inflammation of the pulp, areolation, and degeneration. (Black.) 



more or less continuous uneasiness extending over a long period, 
response of the pulp to all tests becomes diminished and dull. 
Treatment. — Such pulps are to be devitalized and removed. 



The 



Fig. 289 




A, a first lower molar with a cavity at a completely filled by a hypertrophy of the pulp, which 
has grown out through the orifice, exposing the pulp at b. B, a field illustrating the tissue 
of the growth, which is composed almost entirely of granulation-tissue of a very primitive 
type: a, a covering of epithelium presenting papillae; b, epithelium apparently without 
papillae. (Black.) 



364 



CHRONIC DEGENERATIONS OF THE PULP. 



CHRONIC HYPERTROPHIC PULPITIS. 

When the pulp is exposed over a wide area, long-continued chronic 
inflammation may lead to an enlargement of the organ with a pro- 
trusion of altered pulp-mass through the orifice of exposure, producing 
the condition known clinically as fungous pulp. When the growth 

Fig. 290. 




Hyperplastic myxomatous pulp, which filled a carious cavity : m, lobules made up of papillae of a 
myxomatous structure, rich in capillary and venous bloodvessels ; G, calcareous globule ; 
e, epithelial cover of papillae. X 10. (Bodecker.) 



extends beyond the boundaries of the orifice and then increases in bulk 
it forms a pedunculated mass to which the term polypus of the pulp has 
been applied. 

Morbid Anatomy and Pathology. — The growth has its origin in a 
chronic inflammation of the body of the pulp ; the organ swells, and 
contact with the sharp edges of the orifice of exposure excites a con- 
tinued irritation leading to further proliferation of the cells of the 
inflamed part, so that a large mass of embryonic tissue is formed 



CHRONIC HYPERTROPHIC PULPITIS. 



365 



(Fig. 289), termed by Black granulation-tissue of a low type. As in 
the granulation-tissue of repair, bloodvessels grow into this mass 
(Fig. 290), so that it may bleed at a slight touch. Black noted in his 
case illustrated, a covering of squamous epithelium upon the periph- 
ery of the growth, which might be interpreted as the transformation 
of mesoblastic into epiblastic tissue, but the correct explanation beyond 
doubt is that advanced by the same author, that the epithelium is trans- 
planted from the gums, and grows after the manner of a skin-graft. 

These growths may undergo further changes ; higher organization of 
the granulation-tissue occurs and fibrous tissue is formed ; the cells may 
undergo degenerations, first granular, then fatty, and suppuration and 



Fig. 291. 




Acute pulpitis : S, secondary dentin ; B, bay-like excavations filled with medullary or inflam- 
matory corpuscles : V, transverse section of a bloodvessel ; M, multinuclear body. X 300. 
(Bodecker.) 

gangrene may occur. Tomes l records a case where calcification of a 
hypertrophied section of a pulp occurred ; but as the case was due to 
traumatism (fracture of a tooth), different vital conditions existed from 
those in the cases under discussion. Actual calcification of the mass 
is scarcely possible, although calcareous degeneration may occur (see 
Chapter XVIIL). 

Resorption of the walls of the pulp-chamber may occur as an 
accompaniment of chronic pulpitis. What appears to be an idiopathic 
dentin-resorption is described in Chapter XVII. Black records a case 

1 Dental Surgery, 3d ed. 



366 



CHRONIC DEGENERATIONS OF THE PULP. 



Fig. 292. 



where after pulp-capping in a lower molar and the insertion of a large 
gold filling the tooth was examined at the end of ten years ; for two or 
three years the pulp had given evidences of irritability, and when the 
pulp was removed the pulp-chamber was found enormously enlarged 
and opening into the pericementum between the roots of the teeth. 
Fig. 291 exhibits resorption of previously formed secondary dentin 
with the probable agency through which the resorption is brought 
about. The area of resorption is invaded by numerous multinucleated 
cells, which are evidently performing the function of odontoclasts. 

Symptoms. — The symptoms of chronic pulp inflammations and 
degenerations are usually those of long-continued discomfort, with 
reflex pains, which rarely persist into the latest stages of degeneration. 
The response to heat and cold, present at first, declines until the pulp 
scarcely reacts, and then but slowly. 

No nerve-fibres develop in the hypertrophic pulp-tissue, so that the 
new growth has no sensitivity in itself, although pressure upon it may 
cause sharp pain through the still vital Dulp-nerves themselves. 

Diagnosis. — The only condition with which hypertrophic pulp may be 
confounded is a pedunculated growth of gum-tissue through a cavity at the 
neck of a tooth beneath the gum-margin. It is important to differentiate be- 
tween these conditions, because if an appli- 
cation of arsenical paste be made to a fun- 
gous gum, the destruction of tissue may ex- 
tend into the sound pericementum. The 
physical appearances of the two are alike : 
they both bleed freely and have about the 
same degree of sensitivity. If the de- 
generative changes have not involved 
the entire substance of the pulp, a reac- 
tion to cold may be secured, which will, 
of course, determine the diagnosis. After 
isolating the tooth under rubber-darn a 
spray of ethyl chlorid is directed against 
the polypus, and when it is entirely insensitive, a sharp blade is passed 
entirely around the periphery of the carious cavity detaching the fun- 
gous mass. The source of the tumor may then usually be clearly seen. 
If any doubt exist, the cavity is freely syringed with antiseptics, such 
as pyrozone or meditrinia ; a pellet of cotton saturated with the same 
is inserted and over it temporary stopping is firmly packed. If the 
pulp be the seat of the growth, it may rebel against the pressure, and 
require a less firm dressing, so that slight reaction to the pressure is to 
be regarded as evidence that the growth arises from the gum. 
Treatment. — Devitalization and extirpation of the pulp. 




A 




A, hypertrophy of gum similating fan 
gous pulp, B. 



DEVITALIZATION OF THE DENTAL PULP. 367 

DEVITALIZATION AND REMOVAL OF THE DENTAL PULP. 

It will have been noted in the immediately foregoing chapters, that 
the intentional devitalization and removal of the dental pulp are de- 
manded as an indicated therapeutic measure in pulp diseases which tend 
to self-destruction of that organ. The one universal method of accom- 
plishing the death of the pulp en masse is by applications of arsenic 
trioxid — arsenious acid. Although other means have been suggested and 
adopted, none is so certain and effective as^his one. After freely expos- 
ing the organ to be destroyed, a general anaesthetic (nitrous oxid) has 
been administered, and the pulp removed while the patient is in the 
anaesthetic state. Sprays of rapidly vaporizable substances, such as ethyl 
or methyl chlorid, directed against the exposed pulp, the tooth being 
isolated under rubber-dam, will in many cases render the pulp entirely 
insensitive, although, as a rule, they fail to entirely anaesthetize to the 
apical foramen. Applications of even saturated solutions of cocain 
being ineffective, it has been suggested to inject cocain into the 
pulp : the surface of the pulp is benumbed by applications of strong 
solutions of cocain, the needle of a hypodermic syringe containing a solu- 
tion of cocain hydrochlorid (from 4 per cent, to 10 per cent.) is quickly 
thrust into the pulp-canal, and a drop of the solution forcibly injected ; 
in a few seconds the pulp may be so benumbed that it may be removed. 1 
This procedure, however, appears to fail as often as it succeeds. 

Cocain cataphoresis is usually effective, although in conditions of 
active hyperaemia and inflammation even the maximum current and 
saturated solutions of the alkaloid may fail to subdue the irritability 
of the pulp. The pulp may be destroyed piecemeal by applications of 
strong caustics, such as zinc chlorid or chromic acid and sodium or 
potassium hydrate, but their action is slow and the operation tedious ; 
moreover, it is not without danger ; in addition, the application of these 
agents in sufficient strength is usually followed by severe paroxysms of 
pain. 

Arsenious acid — arsenic trioxid — is prompt, certain, and complete in 
its action and has maintained its position in dental therapeutics since 
introduced by Spooner for this purpose in 1836. The progenitor of all 
present arsenical pastes was the formula of J. D. White, given some 
forty years ago : 



aa 



]^. Arsenious acid j 
Morphiae sulph., j 
Carbolic acid, q. s. ft. paste. — M. 

1 Maxfield, Proc. New Jersey State Dental Society, 1894. 



368 CHRONIC DEGENERATIONS OF THE PULP. 

This was followed twenty -five years ago by that of J. Foster Flagg : 

Jfy. Arsenious acid, gr. x ; 

Morphia? ace tat., gr. xx ; 

Ol. carophyllum, q. s. ft. paste. — M. 

The advantages of the latter were demonstrated clinically, and within 
a few years scientifically. The purpose and effects of the ingredients 
of arsenical pastes will become more evident after an examination of 
the effects of arsenic upon the pulp. 

Effects of Arsenic on the Pulp. — Since the introduction of arsen- 
ical preparations definite physiological effects have been noted following 
their use. First, a grumbling pain, rising in a few hours to acute par- 
oxysmal pain ; then a gradual and in some cases a sudden cessation of 
pain, after which the pulp fails to respond to applications of cold. 

These effects were explained 1 as follows : " A minute portion of the 
arsenic being introduced into the pulp-circulation, acts as a dynamic, 
vital irritant, causing determination of blood to the part " (i. e., arterial 
hyperemia"), and gives rise to the throbbing pain. Congestion (presum- 
ably venous hyperemia) follows, occasioning the cessation of throbbing 
and the appearance of dull, gnawing pain in the tooth. " The death of 
the pulp en masse is due to strangulation of the vessels at the apex of 
the root in consequence of the congestion." 

The subsequent decomposition of the pulp — putrefaction — was 
deemed due to the amount of arsenic absorbed by the pulp prior to its 
death being insufficient to preserve it. Flagg states 2 that tests of pulp 
which have been devitalized by arsenic show but an infinitesimal 
amount of the agent to be present in them. 

The same writer points out the existence of pericemental irritation 
in the last stages of pulp-devitalization ; that is, in from four days to a 
week after the application ; regarding it as not due to the irritation pro- 
duced by the arsenic, but to an extension of the vascular condition from 
the pulp ; the pericemental disturbance is limited, ceasing in a few 
hours or a day or two. 

A rkovy 3 was the first to point out the details of the action of arsenic 
upon the dental tissues : 

" 1. As 2 O s brought into contact with the tooth-pulp acts in the follow- 
ing way : a certain degree of inflammatory hypersemia, total or partial, 
depending upon the quantity of the agent applied, sets in ; the blood- 
vessels become expanded, and here have a tendency to thrombosis. 
This latter effect may also be in connection with embolism of the capil- 
laries, when the agent is quickly taken up into the bloodvessels. 

1 J. Foster Flagg, Dental Cosmos, 1877. 2 Ibid. 

3 Transactions Internal. Med. Cong., London, 1881. 



DEVITALIZATION OF THE DENTAL PULP. 369 

" 2. As 2 O s produces no coagulation of tissue whatever. 

" 3. It has a specific influence upon the blood-corpuscles, combining 
with the haemoglobin to form a compound of arsen-hsemoglobin, and of 
this chemical process there seems to be evidence in the profuse yellow- 
ish tinge of the whole pulp-tissue and in the discoloration of blood in 
several of the bloodvessels. 

u 4. In nearly every case it is taken up in substantia (in form of 
molecules) into the blood-ways ; when there it produces, besides the 
above-mentioned changes, granular detritus of the contents and ansemic 
collapse — shrinkage, the latter effect being brought about nearly exclu- 
sively in cases where greater doses were used. 

" 5. The bulk of the pulp-tissue — viz., connective-tissue fibres and 
odontoblasts — undergoes no change whatever ; not so the connective- 
tissue cells, which increase three or four times their normal size. 

" 6. The special action of arsenic trioxid upon the nerve-elements 
consists in the following : the neurilemma is only so far influenced that 
its nuclei are somewhat increased ; a more essential change takes place 
in the axial part, where, after the application of more than one mgrm. 
granular destruction of myelin sets in, and the axis-cylinder commences 
here and there to disappear. A very surprising alteration may be seen in 
the notchy tumefaction of the axis-cylinder, described heretofore almost 
only in cases of central lesions. 

"7. All these alterations occur in and among normal-looking tissue. 

" 8. The action of arsenic trioxid is macroscopically exhibited by a 
brownish-red tingeing of the whole or of certain parts of the pulp- 
body, as well as of the neighboring dentin and the cementum, this latter 
in cases treated with greater doses — viz., two to five mgrms. This 
alteration is most expressed at the top of the crown-pulp and at the 
apical one-fourth to one-third part. This circumstance may be con- 
sidered as an external evidence of the devitalization being completely 
attained to." 

In some cases the pinkish discoloration of the dentin may be marked ; 
the broken-down corpuscles of the extravasated blood have their color- 
ing-matter taken up by the odontoblasts, and being distributed through 
their protoplasmic processes produce a condition technically known as 
suffusion. The same result may be an attendant upon injury to the ves- 
sels from other causes, from sudden thrombosis, as when teeth are moved 
too rapidly in regulating. 

Miller's experiments 1 upon the tails of mice, made without and with 
rings at the root of the tail to simulate the surroundings of the apical 
vessels of a tooth ; made without and with encasement of the tails in 
plaster-of-Paris to imitate the rigid surroundings of the dental pulp : 

1 Dental Cosmos, 1894. 
24 



370 CHRONIC DEGENERATIONS OF THE PULP. 

showed that in the absence of the plaster encasement, enormous oedema 
of the tail was produced and a sensory paralysis of the hind limbs ; 
complete anaesthesia of the tail occurred in forty-eight hours. " The 
action of arsenic appeared somewhat accelerated when a glass ring 
was applied close to the root of the tail. In more than forty cases 
there was not one in which the action of the arsenic extended beyond 
the ring, and the action was not appreciably affected by enclosing the 
tails in plaster casts. The action of the arsenic is of a progressive 
nature, beginning at the point of application and extending gradually 
in each direction." The indication is, therefore, that a minute portion 
of the arsenic is taken into the pulp ; this may be either through the 
odontoblastic processes in cases of non-exposed pulps, or, when exposed, 
by the cells themselves, and causes violent reaction of the vessel-walls, 
which dilate to their utmost ; extravasation of corpuscles occurs and 
circulation is checked at the end of the root, the pulp-vessels are me- 
chanically occluded, so that no absorbed arsenic is carried beyond the 
pulp extremity. The arsenic exercises its paralyzant and degenerative 
influence upon the nerves of the pulp, after first inducing a violent irri- 
tation, which may be due to the specific action of the arsenic upon the 
nerves or to the intense hyperemia. The strangulation theory can- 
not, however, hold in all cases, for progressive death of structures 
free to expand occurs after applications of arsenic, so that the specific 
and gradual action of the poison must be the important factor. Strang- 
ulation would imply an always sudden death of the pulp en masse, 
Which evidently does not always occur, for complete death of the organ 
may be gradual and require several days. In other cases repeated 
applications may be necessary. 

These experiments illustrate the danger of making arsenical appli- 
cations to immature teeth or those in which resorption of the roots is in 
progress. If the full constriction of the apical foramen has not 
occurred, it is possible that a portion of the arsenic may be carried 
beyond the apex of the root into the pericementum. This danger, it 
may be remarked, has been recognized for the past thirty years. 

Variations in the Action of Arsenic. — In most cases of fully 
formed teeth in young adults, an application of arsenical paste directly to 
the exposed pulp will be followed by the complete death of the organ 
in forty-eight hours. At the expiration of that time a sterilized broach 
may be passed almost to the apex of the root and the pulp removed 
en masse without pain. If pulp-nodules exist, the action of the arsenic 
may be delayed or in some cases be almost nil. In calcareous and other 
chronic pulp-degenerations the action is also delayed. If arsenical appli- 
cations are made over a layer of dentin, the same delay is noted, and is 
increased in very mature teeth. 






DEVITALIZATION OF THE DENTAL PULP. 371 

Some pulp, irrespective of the pulp condition, exhibits a peculiar 
idiosyncrasy in resisting the action of arsenic, requiring large doses and 
a week or longer application before succumbing. 

Form in which Used. — Miller 1 has pointed out the influence 
exerted by the several agents used in conjunction with the arsenic. The 
constituents of the common prescription, 

R. Acidi arsenosi, ) 

Morpniae acetatis, J 
Acid, carbolici, q. s. ft. paste. — M., 

were supposed to have the following properties : the arsenic trioxid 
being the devitalizing agent ; the morphia is used to lessen or deaden 
the pain of the application ; the carbolic acid is an analgesic men- 
struum. ' Carbolic acid and other coagulants produce an eschar, a 
coagulum, which delays the absorption of the arsenic, so it should 
be discarded. It has always been questioned just what extent of 
analgesic effect morphia possessed ; some say none, holding that the 
lessened pain is due to the reduction of the amount of arsenic applied. 
Certainly, the painful effects of the poison do appear to be modified by 
the size of the dose employed. Iodoform, also used as an analgesic 
ingredient in some prescriptions, is of doubtful value. Cocain, natu- 
rally, was made one of the ingredients of arsenical pastes soon after 
its introduction into the materia medica. The usual prescription at 
present is : 

1^. Acidi arsenosi, gr. x ; 

Cocain. hydrochloride gr. xx ; 

Ol. cinnamomi, q. s. ft. paste. — M. 

Miller suggests using thymol in connection with arsenic, it being 
both analgesic and antiseptic. He offers the following general rules as 
deductions from his observations : 

1. The rapidity and intensity of the action of arsenious acid depend, 
under certain circumstances, to a very considerable degree upon the 
substance or substances with which it is incorporated. 

2. Where there is but a small point of exposure, and in particular 
where extensive calcification has taken place in the pulp, escharotics 
should be avoided, since the coagulation of the tissue retards the absorp- 
tion of the arsenic. This retardation is but slight where there is a 
broad surface of exposure. In stubborn cases, where applications of 
the ordinary paste fail to effect the devitalization, a paste consisting of 
arsenious acid in oil of cloves, glycerin, or salt solution should be 
employed, undiluted by any third constituent. 

1 Dental Cosmos, 1894. 



372 CHRONIC DEGENERATIONS OF THE PULP. 

3. Thymol is worthy of a trial as a substitute for morphia, on 
account of its anaesthetic and antiseptic properties. 

4. For devitalizing pulps of temporary teeth or remains of pulp- 
tissue in root-canals, arsenious acid, if employed at all, should be 
diluted with two or three parts of some other constituent (thymol, zinc 
oxid, morphia, iodoform). 

Cobalt was introduced by Robert Arthur as a devitalizing agent some 
forty years ago. Within recent years it has been employed, notably 
by the Herbst method (which see), to destroy pulps. The cobalt paste 
of Herbst was analyzed by E. C. Kirk ' and found to consist of metallic 
arsenic and cocain hydrochlorid. Kirk suggests that free acids which 
cocain salts may contain, or the chlorin from the chlorid, may combine 
with the metallic arsenic and form soluble salts. Commercial cobalt 
will certainly devitalize the dental pulp, but it is in consequence of the 
arsenic contained in it. 

Mode of Application. — It is always to be borne in mind that arsenic 
acts upon all living tissue in the destructive manner that it does upon 
the dental pulp, so that the first consideration in making an arsenical 
application is the precise placing and sealing of the paste so that none 
of it shall come in contact with any vital tissue other than the pulp. 
Second, in conditions of venous hyperemia or inflammation arsenic, 
instead of exercising its actively destructive property, serves but to 
exaggerate the existing vascular conditions with the attendant symp- 
tom, pain. Third, but a minute quantity of arsenic is required to kill 
a pulp ; and if an excess be used, the attendant pain is much increased. 
Fourth, if any pressure be exerted upon the pulp by the material used 
to seal in the paste, the pain will be increased in the degree of the 
pressure. Fifth, in the vast majority of- cases the pulp-cavity is the 
seat of infection, so that careful sterilization should precede the appli- 
cation of arsenic. Sixth, to insure accuracy of placement, freedom from 
leakage, and sterilization, the application of the rubber-dam should pre- 
cede the placing of the arsenical paste. 

In the vast majority of cases arsenical applications are made directly 
to the point of exposure in the cavity of decay. In case the gum over- 
hang the cavity-margins, it must be removed until the margins are clear 
and visible. The cavity is syringed repeatedly with warm pyrozone ; 
and a pledget of cotton saturated with meditrina, thymol (saturated solu- 
tion), or hydronaphthol (alcoholic solution), and over this a pellet of cot- 
ton which has been dipped in sandarac varnish is placed. The dressing 
must be renewed in twenty-four hours. Coagulating antiseptics should 
not be used, as they form a coagulum upon the surface of the pulp and 
interfere with the action of the arsenic. If the cavity be upon the buccal 

1 Dental Cosmos, 1893, p. 247. 



DEVITALIZATION OF THE DENTAL PULP. 373 

face of a molar, or in a situation where the gum-tissue has hypertrophied 
and covers the cervical portion of the cavity as a bulbous mass, the re- 
dundant portion may be trimmed away by means of a sharp, curved 
bistoury or gum-lancet. 

As soon as the cervical border of the cavity is clear of the overhang- 
ing gum it is syringed with warm antiseptics and the rubber dam ad- 
justed. The softened dentin is freely cut away until the cavity has a 
retentive form and the area of exposure is clearly outlined. If the 
pulp be the seat of immediate or very recent hyperemia or inflamma- 
tion, anodyne antiseptics should be sealed in the cavity for a day or two 
before making the arsenical application. An admirable prescription in 
this connection is thymol or menthol with cocain made into a paste with 
glycerin ; a pledget of cotton dipped in this mixture and laid upon the 
exposure is sealed in the cavity by means of softened temporary stop- 
ping applied without pressure. 

If the cavity be inaccessible, where the rubber -dam cannot be used 
to exclude fluids, and where an arsenical application cannot be made 
with precision and without fear of dislodging it while it is being sealed 
in, it is advisable to form a special cavity for its reception. This should 
always be made when possible in a line of direct approach to the pulp- 
canals. The cavity is to be made as deep as possible without plunging 
into the pulp. As a rule, in the conditions demanding extirpation of 
the pulp the dentin is insensitive or nearly so, so that the pulp may 
be almost exposed without pain. An exception to this, however, is 
found when pulp-nodules exist, when the dentin may be exquisitely 
sensitive. In these cases two or more applications of the paste are 
required ; as soon as the pulp can be exposed, a direct application of the 
paste is to be made. 

To make the application, the cavity is sterilized, placed under 
rubber-dam, and an application of pyrozone is made, remaining five 
minutes or longer ; the cavity is dried, and a piece of cotton, not larger 
than a pin-head, is to have a minute portion of the paste placed upon it, 
and then laid gently upon the spot of exposure. It is the general 
practice to seal in the arsenic with cotton and sandarac, or temporary 
stopping. The first becomes very foul in twenty-four or forty-eight 
hours, and swells, causing pressure upon the pulp and much pain. 
Temporary stopping, made very soft, may be manipulated so that it 
causes no pressure, but some slight pressure is the rule ; so that a thin 
paste of zinc phosphate is to be recommended as the sealing-material. 
" Flowed over the arsenical application and removing the rubber-dam 
before the cement has hardened will diminish or prevent the pain inci- 
dent to the application and render the cement easy of removal." 

1 Miller. 



374 



CHRONIC DEGENERATIONS OF THE PULP. 



Instead of placing the paste upon a pledget of cotton, cotton-fibre 
may be rolled in an arsenical paste, dried, and preserved ; in this con- 
dition it is known as devitalizing fibre. The advantage of this fibre is 
that a dry arsenical application may be made to the pulp, so that there 
will be no danger of oozing. The length of time required for devitaliza- 
tion is usually about twenty-four hours, although in a large number 
of cases sensitivity will still exist at the upper third of the canal por- 
tion of the pulp at the end of two days. At the end of four or five 
days the pulp will in most cases have completely sloughed at the apex. 
To relieve unusual pain following an arsenical application general 
anodynes or sedatives will at times be required. While morphia 
sulfate, gr. jr, will deaden the pain, the after-effects of morphia are 
uncomfortable. The coal-tar derivatives are useful ; gr. x of ammonol, 
or phenacetin and exalgin, da. gr. iij, administered at the time of the 
application and repeated upon retiring, will act effectively. 

An annoying type of case is where approach is to be made in an 
approximal cavity with a cervical margin beyond the gum-margin, 
where access to the pulp-canals will be direct after devitalization, and 
yet the cavity cannot be kept dry. Such cases are managed after the 
following manner : a small piece of temporary stopping is softened and 
pressed against the cervical wall of the cavity, but not covering the 
pulp-exposure ; the stopping is then moulded against the gum press- 
ing it back (Fig. 293) : this guard accurately 
placed will protect the gum against arsenical 
poison by preventing oozing of the latter from 
about the cervical edge. An application of de- 
vitalizing fibre is then made, and sealed as usual. 
Cervical cavities not having a retentive 
form, and abraded teeth, offer difficulties, which 
are overcome by drilling a special pit for the 
reception of the paste. 
In cases where there are pulp-nodules, and where chronic degen- 
erations of the pulp exist, the arsenic is removed at the end of the 
usual devitalizing period and free entrance is made to the pulp, cutting 
away all insensitive portions ; if pulp-nodules can be lifted away pain- 
lessly, they are removed, and a fresh application of arsenic is made, 
to remain again several days. In all of these cases, to effectually devi- 
talize it may be necessary to apply a paste of arsenic trioxid in glycerin, 
or in one of the essential oils. 1 

Removal of Pulp. — At the end of four or five days the dressing 
seal, and cotton containing the paste are removed, the cavity freely 
syringed with hydrogen dioxid, and the rubber-dam applied. Large 

1 Miller. 



Fig. 293. 




DEVITALIZATION OF THE DENTAL PULP. 375 

sterilized rose burs are used to open the pulp-chamber freely and to 
remove all softened dentin (all softened dentin being always removed 
from pulpless teeth). 

The cavity is now to be given such form that pulp-broaches may be 
passed directly and freely to the apex of each root. This rule is to be 
followed, no matter how much tooth-substance is sacrificed to carry it 
into effect. As the future health of the tooth depends almost entirely 
upon the thoroughness with which each canal is cleansed, sterilized, and 
hermetically sealed at the apex, it is evident that the removal of crown- 
tissue is a small evil compared with incomplete entrance to and 
cleansing of a canal. 

A new and perfect pulp-broach is dipped in carbolic acid and gently 
passed to the apex of the root ; the teeth of the broach are turned away 
from the pulp until the instrument is fully inserted, when the broach 
is turned so that its teeth shall engage the entire length of the pulp, 
which may then usually be removed entire. In multirooted teeth, after 
removing the body of the pulp, the largest canal is first entered and 
the pulp removed ; this canal is then to be loosely filled with a twist 
of cotton containing an antiseptic ; carbolic acid, formalin in 2 per cent, 
solution, or hydronaphthol. The next largest canal is cleansed and 
treated in the same manner, and after this the smallest canal. 

Removal of the pulp entire may nearly always be assured if, after 
an arsenical application have been in the tooth for three or four days, 
it be removed, and a dressing of formalin, 5 per cent., be inserted for 
several days. The pulp is rendered tougher by this agent. 

In canals too small to admit the pulp-broaches, cleansing and uniform 
enlarging of the canals are accomplished by means of chemical agents. 
The general cavity-wall is varnished to prevent the action of the 
acid upon the dentin, and by means of a pair of Flagg's dressing- 
pliers or a minim-dropper a drop of sulfuric acid (50 per cent, solu- 
tion) is deposited at the mouth of the canal to be operated upon. The 
finest size of Donaldson's canal-cleanser is then passed into the canal 
as far as it will go, using a pumping movement to carry the acid further 
into the canal and to scrape the canal-walls softened by the action of 
the acid. 1 The acid chemically destroys any organic matter — i. c, pulp- 
tissue — present, releases the calcium of the dentin from its combination, 
and forms calcium sulfate, which is mechanically removed by scrapers. 
The operation is continued until the apex of the root is reached. 

If all of the operations have been carried out with antiseptic pre- 
cautions, sterilizing the cavity, placing it under rubber-dam, drenching 
the pulp with antiseptics, and using none but sterilized instruments, the 
canals are now in an aseptic condition and are to be hermetically 
1 Callahan, Proc. Ohio State Dental Society, 1894. 



376 CHRONIC DEGENERATIONS OF THE PULP. 

sealed — filled. If the pulp have been removed within two days from 
the application of the arsenic, bleeding may follow the extirpation 
of the pulp, or a mild and what should always be a transient peri- 
cementitis may arise. In case of bleeding, applications of hydrogen 
dioxid will act as a styptic and also decompose and remove the blood. 
The canal should not be sealed until the bleeding ceases. The transient 
pericementitis is most common in cases where slight sensitivity of the 
apical portion of the pulp existed at the time of extirpation, and is 
evidenced by soreness of the tooth, tenderness upon percussion. This 
irritation may be pronounced if immediate root-filling, the usual pro- 
cedure in cases of intentional devitalization and removal of the pulp, 
be practised. If tenderness appear during or immediately after extir- 
pation, it promptly subsides upon filling the pulp-canals with a saturated 
solution of menthol in chloroform, filling the canals loosely with cotton, 
hermetically sealing the cavity, and painting the gum overlying the 
tooth with tr. iodin. The canals should remain unfilled for a week, 
until all evidences of pericemental irritation subside. Before filling, 
the canals should be thoroughly washed with hydrogen dioxid. 

The Root Canal-filling". — The features to be possessed by a canal- 
filling should be : first, it should be non-irritating ; secondly, it shall 
hermetically seal the canal ; thirdly, it shall be unalterable in the condi- 
tions surrounding it. If possible, it should be continuously antiseptic, 
and be removable if subsequent conditions ever demand its removal. 
The materials most employed are zinc oxychlorid, and gutta-percha, 
solid and in solution, or combinations of both. 1 

The present tendency is to substitute melted paraffin, containing 
antiseptics, for other materials. The choice is clearly indicated as a 
rational therapeutic measure. Certainly it will be evident from a study 
of the forms and variations of pulp-canals (see Chapter VIII.) that 
only pastes or fluids can fill perfectly all of the irregular spaces found 
in pulp-canals. 

Paraffin fulfils all of the conditions required of a correct canal- 
filling. In using this material a small piece is caught between the 
jaws of a pair of Flagg's dressing-pliers and held over a flame until 
melted ; then the closed beaks are placed as high up the canal as 
they will go, and slowly withdrawn ; gradually opening the beaks, the 
fluid runs up the canals of even upper teeth. A warm, smooth probe 
is then used to pump the fluid paraffin into all parts of the canal. Into 
the fluid paraffin a long slender metallic point of some unoxidizable 
material — gold, platinum, or aluminum — is warmed and thrust. The end 
of the metallic point is left projecting into the pulp-chamber, so that 
should removal of the canal-filling ever become necessary, a hot instru- 
1 See American Text-book of Operative Dentistry. 



DEVITALIZATION OF THE DENTAL PULP. 377 

merit may be laid against its exposed end, melting the paraffin, when the 
point may be withdrawn. 

Accidents -with Arsenic. — If arsenic trioxid come in contact with 
any vital tissue, it exercises its destructive influence upon it. The 
most common accident is the oozing of arsenic from beneath a seal- 
ing application, and its contact with gum-tissue. The effect of the 
arsenic in these cases depends upon the point of lodgement. Arsenic 
trioxid being insoluble in the fluids of the mouth, may remain lodged 
in a minute crypt and exercise its destructive influence. Accidents in 
this direction should be guarded against by carefully pressing away the 
gum from cavities prior to using the arsenic ; by using a very minute 
portion of the latter and placing it with precision ; by the use of small 
pieces of devitalizing fibre instead of paste. Oozing, however, should 
never occur, and when it does, it is evidence of lack of care, or, worse, 
of gross carelessness upon the part of the operator. 

Arsenical applications sealed in with any material other than zinc 
phosphate should be examined at the end of twenty-four hours to see 
that there is no evidence of irritant poisoning of the soft tissues. The 
evidences of the presence of arsenic in contact with gum-tissue are : 
deep purple engorgement of the gum and subsequent sloughing of the 
poisoned tissue. If a portion of the arsenic gain lodgement far beneath 
the gum-margin, near the pericementum, it may exercise its necrotic 
effects upon the latter tissue, destroying it in part or in whole. Flagg 
has recorded cases in which necrosis of the contiguous alveolar process 
has occurred. 

The only cure of the condition consists in the thorough removal of 
every particle of the arsenic. Being insoluble, it must either be washed 
away mechanically or be transformed into a soluble or an inert body. 
The swollen gum-tissue is to be pressed away from the tooth and jets of 
w T arm water thrown forcibly into the space in the hope of dislodging 
and washing away the insoluble arsenic. A freshly prepared mass of 
ferric hydrate (the antidote of arsenic), made by adding magnesium oxid 
to ferric chlorid, may be packed into the pocket, but its utility is ques- 
tionable. The free use of iodin tincture in one case appeared to give 
good results, perhaps from the formation and washing away of arsenic 
iodid. Any projecting masses of cedematous gum should be cut away, as 
they are dead and will slough at any rate, and a freer access to deep 
parts is had — the blood-flow may itself wash away the arsenic. The 
forcible Avashing should be prolonged and repeated. The tissue to 
whatever extent it has been devitalized by the arsenic will slough away. 
Dental literature contains the records of a few cases in which the 
action of arsenic has extended beyond the ends of the roots of teeth, 
when an arsenical application has been made far up a canal to destroy 



378 CHRONIC DEGENERATIONS OF THE PULP. 

a vital pulp-filament. One case is recorded where an application was 
carried bodily beyond the apex of the root. The records of these cases 
are not sufficiently clear to formulate rules as to the extent of destruc- 
tive action caused by minute portions of arsenic. A priori, they would 
be governed by the amount of arsenic which gains access to the peri- 
cementum ; certainly more or less alveolar necrosis would be the natural 
result. The insertion of a broach into and beyond an arsenical appli- 
cation high up in the root, into the apical foramen or beyond, may no 
doubt account for rare cases of uncontrollable pericementitis, ceasing 
only with the loss of the tooth, and, it may be, of contiguous bone. 

PARTIAL REMOVAL OF PULP. 

The cobalt method of pulp-treatment lias been alluded to. Win. 
Herbst, of Bremen, advanced the idea that if the bulbous portion of 
the pulp be devitalized by cobalt and removed, leaving the root-portions, 

the latter will remain vital, if protected after a 
Fig. 294. manner described by him. The bulbous portion 

of the pulp is cut away and the pulp-chamber en- 
larged by means of large rose burs. Over the pulp- 
stumps a cylinder of tin-foil is laid, and burnished 
to fit the floor of the pulp-chamber, without pressure 
upon the pulp-stumps (Fig. 294). Over this a fill- 
ing is placed. Herbst claims, endorsed by Bo- 
decker, 1 that the pulp-stumps will remain vital. 
Were this to be depended upon, it would be a marked saving of time 
and trouble, and would lessen the chances of pericementitis subsequent 
to pulp-removal ; but when it is known that the cobalt of Herbst is metal- 
lic arsenic, the ultimate death and decomposition of the pulp-remnants 
seem almost inevitable. 

MUMMIFICATION OF THE PULP. 

As early as the introduction of arsenious oxid as a devitalizing 
agent it was noted that a certain percentage — or, rather, an uncertain 
percentage — of cases gave evidence of little or no disease after the 
application of arsenic and its sealing in a cavity by filling. Later, it 
was found that applications of powerful antiseptics to exposed pulps 
not infrequently were followed by a long-continued quiet of that organ ; 
still later, when more definite knowledge was possessed of the pathologi- 
cal results which might follow the leaving of portions of pulp-substance 
in the canals of teeth after devitalization by arsenic, it was observed 
that after saturating the canals with creosote or zinc-chlorid solutions, 

1 Anatomy and Pathology of the Teeth. 




MUMMIFICATION OF THE DENTAL PULP. 379 

many cases gave little or no evidence of pericemental disturbance 
thereafter. 

While it is unquestionably preferable to always thoroughly remove 
the last vestige of devitalized pulps, the time, care, skill, and expense 
involved in perfect cleansing are drawbacks to its universal practice. 
The only other possible solution of the difficulty is to so alter the tissue 
not removed that it shall remain permanently aseptic, and, if possible 
to make it so, antiseptic. 

Observations derived from clinical experience although undoubtedly 
of great and permanent value, are indeterminate, and our truly scientific 
knowledge of this matter dates from W. D. Miller's experiments. 1 
He credits Witzel with the first systematic observations in this direction. 
Witzel, in 1874, " devitalized the crown-portion of pulps by means of 
arsenic, extirpated that portion, leaving the pulp in the canals undis- 
turbed, their exposed ends being treated as freshly exposed pulps." 
This is the method followed by Herbst, who employs cobalt (which is 
native arsenic sulfid or metallic arsenic) instead of arsenic trioxid. 

Miller's experiments have shown that none but the most powerful 
and penetrating antiseptics have value as permanent sterilizers. These 
are the cyanid, bichlorid, and salicylate of mercury, sulfate of copper, 
and oil of cinnamon. Orthocresol, carbolic acid, trichlor-phenol, and 
zinc chlorid penetrate the pulp-tissue rapidly, but are too diffusible, dis- 
appearing in a few weeks. 

He classifies salicylic acid, eugenol, campho-phenique, hydronaphthol, 
a- and /9-naphthol, acetico-tartrate of aluminum, and some essential 
oils, resorcin, thallin, sulfocarbolate of zinc, etc., as being of doubtful 
value. 

Those nearly or quite worthless are iodoform, basic anilin coloring- 
matters, borax, boric acid, dermatol, europhen, calcium chlorid, hydro- 
gen dioxid, sozoiodol salts, tincture of iodin, spirit of camphor, and 
naphthalin. 

The preparation giving the best results consisted of mercuric chlorid, 
0.0075 gram ; thymol, 0.0075 gram, in tablet-form. 

The pulp is devitalized ; the crown-portion and all the root-portion 
readily accessible are removed ; one of the tablets is placed in the pulp- 
chamber, crushed by means of an amalgam-plugger, and covered with 
gold-foil. The mercury salt tends to discolor the crown of the tooth, 
so that its employment should be restricted to the posterior teeth ; 
indeed, the necessity for its use would be, as a rule, found with these 
teeth, being those from which it is most difficult to extract pulp-rem- 
nants. Miller expresses faith in the power of oil of cinnamon to per- 
manently sterilize pulp-fragments. He suggests the experimental 

1 Proc. Columbian Dental Congress, 1893. 



380 CHRONIC DEGENERATIONS OF THE PULP. 

application of the sterilizing tablets to such teeth as are readily salvable, 
yet which are for various reasons " consigned to the forceps." 

Theodore Soderberg, of Sydney, N. S. W., reports excellent results 
from a continuous practice of this method of pulp-sterilization. He em- 
ploys a paste composed of — 

1^. Alum exsic, ^ 

Thymol, V da. 3J ; 

Glycerol, J 

Zinc, oxid., q. s. to make stiff paste. — M. 

He substitutes dried alum for tannin, originally used by him as the 
hardening-agent ; his experiments showed the tannin to be productive 
of discoloration. Mercuric chlorid is set aside for the same reason. 
Oil of cassia employed in the paste also caused discoloration. At present 
Soderberg adds a small quantity of cocain to the paste to prevent the 
pain arising from the action of the dried alum. He states (Nov. 1895) 
that he has in a year applied the paste in 97 cases, and has had no 
untoward results. The method of placing the material is shown in 
Figs. 295 and 296. 

Fig. 295. Fig. 296. 





a, caries exposing a horn of the pulp. a, root-portion of pulp ; b, mummifying paste ; 

c, zinc phosphate ; d, gold or amalgam. 

C. A. Firth, of Queenleyan, N. S. W., 1 advises the omission of zinc 

oxid from the paste, to avoid the formation of the brown tannate of zinc. 

He suggests the use of a mixture of tannic acid and thymol, equal parts, 

made into a paste with glycerol, and applied with ivory instruments, to 

avoid discolorations. He expresses himself as gratified at the results 

obtained. 

1 Dental Cosmos, May, 1896. 



CHAPTER XX. 
GANGRENE OF THE PULP. 

Definition. — By gangrene of the pulp is meant its death in toto from 
being cut off from its nutritive supply at the apex of the root. It occurs 
in two forms, dry and moist. Dry gangrene is the condition known as 
mummification of the pulp. Moist gangrene is associated with putre- 
factive decomposition of the organ. The conditions differ not only as 
to causation, pathology, and morbid anatomy, but in their effects and 
treatment, so that each requires separate consideration. 

Dry Gangrene of the Pulp. 

Definition. — By dry gangrene of the dental pulp is meant its death 
in toto and its subsequent transformation into a dry, shrivelled mass 
occupying the palp-chamber and canal. 

Causes. — The causes of this condition may be divided into physical 
and chemical. The physical causes, so far as known, are direct injury 
or jugulation of the vessels of the pulp at the apical foramen. This 
may be due to blows upon the teeth, to their rapid movement in regu- 
lating, particularly by their forcible movement by forceps, to too sud- 
den and violent wedging, and by non-fixation of the teeth during and 
subsequent to regulating, permitting their undue movement ; by any 
force, in short, which can cause torsion or tension of the vessels at the 
apex of the root. These influences acting upon the apical vessels may 
cause strangulation, and if the access of air and organisms be impossible 
or does not occur, the watery parts of the pulp may be removed, leaving 
the organ as a tough, shrivelled mass. 

The chemical causes include the action upon the pulp of agents 
which have either the power to devitalize it and preserve it, or which 
transform it into a dry, shrivelled, and aseptic mass after its death. 

Nearly all recorded cases appear to have followed the employment 
of zinc oxychlorid as a pulp-capping or a cavity-lining. 

Pathology and Morbid Anatomy. — Upon opening a pulp-chamber 
containing a mummified pulp no odor is emitted, and the pulp is seen 
dark, dry, and shrivelled. In cases of pulp-death under oxychlorid 
caps it is difficult or impossible to determine whether the pulp has 
been killed by the zinc chlorid and preserved by absorption of that 
substance, or whether it has died from other causes and the zinc salt 

381 



382 GANGRENE OF THE PULP. 

has acted as a preservative. Certainly the condition does not appear 
to be recorded in connection with other capping-materials, although 
other antiseptics, such as those described under the head of mummi- 
fying pastes, might undoubtedly produce similar conditions. 

Symptoms. — Unless secondary processes arise, mummified pulps 
give rise to no symptoms, and the existence of the condition is usually 
discovered by accident. Their usual history is as follows : at a previous 
time (perhaps years before), an exposed or almost exposed pulp has 
been covered with a cap or cavity-lining of the oxychlorid of zinc, and 
remained comfortable thereafter. At some subsequent time it may be 
necessary to open the tooth, usually on account of recurring caries : the 
total absence of dentinal sensitivity is noted ; the tooth has changed 
color but little, if at all ; and the operator burs carefully toward the 
pulp to determine its condition. (It should be remarked here that 
absence of dentinal sensitivity in a tooth having normal color and 
which contains a very large filling is an indication of aseptic death of 
the pulp, and the operator should renew all of his antiseptic precautions 
as to isolation of the tooth by the rubber-dam and complete sterilization 
of all instruments, and of the territory of operation.) The burring is 
continued without any evidence of sensitivity, and the instrument is 
fiually felt to pass into the pulp-chamber. There is no odor, no escape 
of fluid ; the pulp is found dry and shrivelled. If sterilized pulp- 
extractors are passed into the canals, the remnants of the pulp may 
be withdrawn, exhibiting none of the usual signs of decomposition, 
such as odor and confluent softening. 

Treatment. — The treatment consists in aseptic cleansing and her- 
metical sealing of the pulp-canal. If the fluids of the mouth be per- 
mitted access to the mummified pulp, infection occurs promptly, and a 
vigorous pericementitis may be lighted up. Whether the dried pulp 
affords a favorable breeding-ground for particularly virulent organisms, 
or whether the apical pericementum in such cases affords a most suitable 
field for their secondary activity, certainly the pericementitis which 
sometimes follows the septic opening of such cases is peculiarly obsti- 
nate. In any tooth which has not suffered any change of color, in 
which dentinal sensitivity is entirely absent, and which was believed 
to contain a vital pulp, precautions as to asepsis and antisepsis should be 
redoubled. The general rule, that no pulp-chamber should be deliber- 
ately opened before adjusting the rubber-dam, has here an increased sig- 
nificance. Every bur that is used should be thoroughly sterilized before 
using. As soon as the pulp-chamber is opened, that cavity is explored. 
A clean, new broach which has been dipped in carbolic acid is carried 
to the apex of the root and withdrawn ; if the pulp be mummified, the 
broach brings it away and exhibits no fluid upon it. If any deposits 



MOIST GANGRENE OF THE PULP. 383 

are found on the broach, it is evidence that some decomposition has 
occurred. The agent indicated in that event is one which will effec- 
tually destroy all organisms which might be present and which will 
chemically decompose — transform into soluble and entirely removable 
substances — the products of decomposition. Sodium dioxid is, therefore, 
the indication. It may be used in 50 per cent, solution pumped into 
the canals by means of aluminum or iridium broaches. After several 
applications of the sodium dioxid solution have been made, the canals 
are to be washed out with a 10 per cent, solution of hydrochloric or 
sulfuric acid and dried. 

No matter what precautions are taken, the possibility of infection 
must always be borne in mind. While pericementitis usually appears 
promptly in these cases, if infection have occurred, it may not arise for 
two or more days ; during this period it is advisable to insert a pro- 
bationary filling, one which can readily be removed if pericementitis 
does arise. This filling may be a mixture of salol and aristol, paraffin 
and aristol, or a twist of cotton saturated with one of the antiseptic oils, 
such as cassia oil. In all cases where incomplete mummification of the 
pulp is suspected, it is a wise precaution to seal in the cavity a 5 per cent, 
solution of formalin for a day or two before broaching, to give assurance 
of complete sterilization. 

Moist Gangrene of the Pulp. 

Definition. — By moist gangrene of the pulp is meant, the death of 
the pulp en masse and its subsequent decomposition by the action of 
putrefactive agencies. As putrefactive decomposition is the essential 
feature in these cases, and that which gives the process its pathological 
significance, the causes, nature, effects, and treatment of putrefactive 
decomposition of the pulp are included under this sub-heading. 

Causes. — The death of pulp-tissue from any cause and its infection 
with the bacteria of putrefaction. The cases are of two types — those in 
which decomposition occurs without the existence of an opening com- 
municating with the exterior and those in which such an opening exists. 
The first class may be subdivided into those in which decomposition 
occurs subsequent to the insertion of a filling which hermetically seals 
the space between the pulp and the exterior, and those in which the 
tooth is non-carious. It is to be recognized that in the absence of 
bacteria putrefaction cannot exist. By putrefaction is meant that serial, 
progressive decomposition through which albuminous substances are 
finally resolved into the end-products, hydrogen sulfid (H 2 S), carbon 
dioxid (C0 2 ), ammonia (NH 3 ), water (H,0), and hydrogen phosphid 
(PH 3 ). One distinguishing feature of the process is the evolution 
of malodorous gases. 



384 



GANGRENE OF THE PULP. 



Fig. 297. 
Pigment. S + haemoglobin. 



Oases of Open Cavities. 

When the pulp of a tooth is exposed and becomes the seat of that 
series of vascular and nutritive disturbances — hyperemia, inflammation, 
and suppuration — eventuating in its gradual death, the necrotic portions 
undergo putrefactive decomposition. Several processes are in operation 

at the same time, so that different por- 
tions of the pulp exhibit differences in 
chemical composition, differences in the 
nature of the infection, and also in the 
pathological conditions existing. For 
example, while the apical portion of the 
pulp is the seat of inflammation and sup- 
puration, the portion of the pulp pre- 
viously destroyed through these pro- 
cesses, is the seat of later stages of chem- 
ical destruction, until that portion which 
was first acted upon is being resolved 
into the end-products of albuminous de- 
composition, of putrefaction (Fig. 297). 
In this serial decomposition albuminous 
substances are first transformed into 
peptones and allied substances, some 
of them being very toxic. Compound 
ammonias, known as ptomams, or ani- 
mal alkaloids, are probably next formed. 
Next the nitrogenous bases — leucin, 
tyrosin and the amins (methyl, ethyl, 
and propyl) — make their appearance 
together with organic fatty acids. Next 
aromatic products, indol, phenol, cresol, etc., and finally hydrogen sulfid, 
ammonia, carbon dioxid, and water. By alternating processes of hy- 
dration, reduction, and oxidation, bodies of increasing simplicity of 
chemical composition are formed. 1 

Miller 2 found in the deepest portions of the degenerating, putrefying 
pulps, where inflammation and suppuration were in progress, a pre- 
ponderance of small cocci and diplococci, and proceeding toward the 
open pulp-chamber an increasing number of large cocci, several forms 
of bacilli, vibrios, and other spirilla?, spirochaetse, and long thread- 
forms (Figs. 298-305). Figs. 304 and 305 are from the same pulp ; 
Fig. 305 was taken from the radicular portion of a pulp which was 
alive and suppurating ; Fig. 304 was from the putrid crown-portion. 

1 Ziegler's General Pathology. 2 Dental Cosmos, 1894. 




COo, NH 3 ; 
H 2 and H 2 S 



Aromatic and 
fatty prod- 
ucts. 



Ptomains. 



Peptones, 
Pus. 



CASES OF PUTREFACTION UNDER FILLINGS. 



385 



Until infection of the pericementum occurs these cases give rise to no 
symptoms, except odor. 



Fig. 298. 




Fig. 299. 




Fig. 301. 




Fig. 300. 



^ 




Fig. 302. 



&o <»— 




Fig. 303. 



Fig. 304. 



Fig. 305. 



!){}(}'»' 



t'tii 



x 



* ;/ 



t'*/ 



*% 



». \ 






Cases of Putrefaction under Fillings. 

When a filling is placed over an infected pulp, or when the pulp 
dies subsequent to the insertion of a filling, the organ undergoes 
decomposition, the decomposition being carried on in this instance 
without the access of air — i. e., is accomplished by anaerobic organ- 
isms. Miller found that bacteria of pulp-putrefaction cultivated in 
gelatin, with and without the access of air, exhibited a difference in 

25 



386 GANGRENE OF THE PULP. 

the poisonous properties of their products. Those developed with 
free access of air produced stronger reaction, and more extensive sup- 
puration than those developed without the access of air. 

Symptoms. — Prior to infection of the pericementum, pulp-putre- 
faction occurring under fillings may give rise to much pain. First, in 
chronic abscess of the pulp, by imprisonment of the pus. Heavy, throb- 
bing pain, indefinitely located, may be felt, and the tooth may be tender 
upon percussion (see Suppuration of Pulp). Applications of heat are 
almost invariably followed by a paroxysm of pain ; the gases of putre- 
faction being expanded by heat, exercise pressure upon the still vital 
portions of the pulp and upon the pericementum ; as regards the latter 
tissue, however, it is probable that poisonous products are by the expan- 
sion of gases forced into it. The relief from pain is in some cases 
almost instantaneous w x hen an opening is made into the pulp-chamber, 
giving vent to the imprisoned gases. 

Oases of Pulp-putrefaction without Previous Caries. 

Under the head of dry gangrene were described several varieties of 
traumatism which caused the death of a tooth-pulp en masse, particu- 
larly in single-rooted teeth. Instead of becoming mummified, the 
necrotic pulp may undergo putrefactive decomposition. It can only be 
a matter of conjecture how the organisms necessary to putrefactive 
decomposition gain access to the pulp. The possibility that organisms 
may make their way through the cementum and dentin at the neck 
of the tooth must be admitted, although its extreme improbability must 
be recognized. The more probable explanation of their presence is that 
they have gained access to the circulation from some other portion of 
the body, and have been deposited in the dead pulp, and, finding there 
a suitable soil, have developed. 

In one class of cases the source of infection is evident. In cases 
of phagedenic pericementitis (which see) the degeneration of the peri- 
cementum may open a direct passageway from the mouth to the tissues 
of the apical space ; the pulp is cut off from its vascular and neural 
connections, dies, and undergoes putrefaction. This condition may be 
noted upon upper molars particularly, where the pericemental degenera- 
tion has involved the apical tissues about the palatal root of the tooth ; 
upon opening the pulp-chamber the pulp is found dead and putrefying 
in Avhole or in part. 

Many of these cases offer no subjective evidences of disturbance, 
attention being directed to the tooth by a growing opacity of the dentin. 
A reaction occurs between the hydrogen sulfid and decomposing haem- 
oglobin (hemosiderin) of the red blood-corpuscles, forming dark com- 
pounds, which infiltrate and discolor the dentin, rendering it opaque. 



CASES OF PULP-PUTREFACTION WITHOUT PREVIOUS CARIES. 387 

In other cases infection of the pericementum may occur, leading to 
chronic pus-formation, with an exit near, or in many cases far distant 
from the tooth. 

A confusing condition clinically is found where one-half of a pulp 
has died and undergone decomposition, as in lower molars, the other 
half remaining vital, although the seat of infection and inflammatory 
action. So far may this condition go, that abscess, acute or chronic, 
may be present upon the root of one tooth long before the second seg- 
ment of the pulp has succumbed. The diagnosis of such cases is made 
by obtaining the painful reaction to heat, and usually some tenderness 
upon percussion upon some particular portion of the tooth ; upon open- 
ing the tooth the peculiar condition described is formed. 

Treatment. — The general principle of treatment is the same in all 
of these cases, no matter to what clinical division they may belong — 
the disinfection of the canals, the removal of all decomposed and 
decomposing pulp-tissue, prevention of infection of the pericementum, 
and hermetical sealing of the apex of the canal. 

In all of the cases the imminent danger, and that to be guarded 
against, is to avoid mechanically carrying a portion, ever so minute, of 
infective material past the apical foramen. There is but one w T ay to 
accomplish this end with certainty, and that is to render the contents 
of the canal absolutely non-infective before mechanical procedures are 
instituted. This implies the use of an antiseptic which will gradually 
diffuse through the putrefying mass to the apex of the root, and one 
which is certainly germicidal. The condition, as shown, is one of 
infection to near the apex, so that any pressure exerted upon the putrid 
mass may force organisms or their waste-products through the apex of 
the root. Many antiseptics have been shown to have the desired power ; 
notably the essential oils of thyme and cinnamon ; carbolic acid and 
other coagulating agents are less diffusible, hence less prompt and cer- 
tain in action ; lysol, an allied substance, is, however, much more dif- 
fusible. Of all present antiseptics solutions of formalin are perhaps 
most effective because most diffusible. 

The first step of operative procedures is gaining access to the putrid 
pulp. As a preliminary, the mouth is washed with antiseptics — hydro- 
gen dioxid, potassium permanganate, or meditrina — and the rubber-dam 
adjusted. The tooth is next drenched with the same antiseptic and 
partially dried. In cases of open cavity loose debris is lifted away, 
without exercising pressure, until full exposure of the pulp-chamber is 
secured. A pellet of cotton saturated with meditrinia (full strength) 
laid gently upon the mass deodorizes it. 

Cases of putrid pulp under fillings, as a rule, are only seen when 
evidences of pericemental disturbance have appeared. Fissure-burs 



388 GANGRENE OF THE PULP. 

are passed around the margins of the filling until it is loosened and 
detached, and free applications of the antiseptic wash made until free 
access to the pulp-chamber is had. 

In cases without cavities or fillings a spear-pointed drill is passed 
by the most direct route to the axis of the pulp-canal. The drill is to 
be advanced gently, so that it will not plunge forcibly into the pulp- 
chamber. In all of these cases, as soon as free access to the pulp-chamber 
is secured, a drop of a 10 per cent, solution of formalin is flowed into 
the cavity and a pellet of cotton wet with the same solution is gently 
laid over it, which is to be sealed in for twenty-four hours by means 
of temporary stopping. 

It is a general clinical experience that in the cases of putrefying pulp 
in non-carious teeth, pericementitis is a frequent sequel to the opening 
of the pulp-chamber. This has been attributed to the entrance of 
organisms by way of the artificial opening made. Other reasons for 
infection would be the access of air to the previously closed cavity, 
favoring the development of virulent organisms already present, but 
inactive on account of an absence of free oxygen ; or, again, the 
mechanical forcing of infective material beyond the end of the root. 
The first cause is scarely probable ; the second more probable ; and the 
third the most probable cause of the infection. Presumptive evidence 
of this is found where, as advised, an application of formalin is placed 
in the tooth for twenty-four hours before any attempt is made at the 
mechanical cleansing of the canals ; subsequent pericementitis rarely 
occurs. 

To remove the contents of the canals after sterilization no agents 
act with such promptness and effectiveness as solutions of sodium 
dioxid, or of Schreier's alloy of sodium and potassium — kalium- 
natrium. The reason for this is clearly seen from a study of the 
nature of the substances contained in the canals, and the reaction 
which occurs when the alkalies mentioned are brought in contact 
with them. Brought into contact with agents containing water, potas- 
sium-sodium immediately causes its decomposition, abstracting HO, 
forming sodium and potassium hydrates ; hydrogen is set free, which 
ignites in consequence of the heat of chemical combination set 
free in the union of the metals with hydroxyl. Sodium dioxid 
brought in contact with organic matter gives up its extra atom of 
oxygen to the latter and is reduced to N 2 0> sodium oxid, which, com- 
bining with water, becomes sodium hydroxid. Sodium hydroxid from 
either source saponifies all fatty matters and dissolves albumin and its 
derivatives. The action of sodium-potassium is very pronounced ; a 
minute portion of the alloy being brought into contact with decom- 
posing organic matter, decomposes its water with such activity that a 



TREATMENT OF MOIST GANGRENE OF PULP. 389 

spark is produced. The germicidal action of the material has been 
attributed to this heat ; the correct explanation is probably the activity 
of sodium and potassium hydrates in their freshly formed state. The 
extra atom of oxygen in sodium dioxid acts as a prompt antiseptic ; 
and the active sodium hydroxid formed fulfils its function as a saponi- 
fying and solvent agent. Sodium dioxid may be used either in dry 
powder or in saturated solution for the purpose named. 

Non-oxidizable metals are to be preferred in making applications of 
these agents ; broaches of aluminum or of iridio-platinum answer the 
purpose. If the material be used dry, either sodium-potassium or 
sodium dioxid, the roughened broach is dipped in the chemical agent 
and passed part way up the canal of the tooth or up the largest canal 
in multirooted teeth ; a vigorous reaction immediately occurs between 
the chemical agent and the canal-contents ; as soon as this ceases the 
canal is wiped out with a wisp of cotton and a deeper application made. 
The alternate application and wiping away are continued until the apex 
of the root is reached. By this time the walls of the canal are seen to 
be distinctly bleached by the action of the oxygen set free. It is always 
to be remembered that this decomposition represents a chemical reaction 
in which there is a distinct quantitative relation between the amount of 
decomposer and decomposible matter : an excess of the decomposer is 
desirable or even essential. In the vast majority of cases an error is 
made the other way. The operation of thoroughly decomposing the 
contents of a pulp-canal and dentinal tubuli containing decomposing 
albuminous matter, requires a considerable length of time, as will be 
seen in the following test. After having spent a half an hour or 
longer in carrying successive portions of the active agents named 
into pulp-canals, say of a lower molar, until all evidences of chem- 
ical reaction cease, then forcibly syringe the canals witli hydrogen 
dioxid or a 10 per cent, hydrochloric acid solution until efferves- 
cence ceases ; dry the cavity and canals, insert a ball of cotton in 
the pulp-chamber, leave the canals unfilled, and seal the crown-cav- 
ity for several days ; at the expiration of this time unseal the tooth, 
remove the cotton, and in a number of cases the odor of putrefaction 
may be detected. The sodium oxid solution slowly makes its way into 
the dentinal tubuli, decomposing their contents. If, now, a 10 per cent, 
solution of sulfuric acid be pumped into the canals, it effects the decom- 
position of the sodium compounds present, forming with Na 2 2 1 

Na 2 2 + H 2 S0 4 = Na 2 S0 4 + H 2 2 , 

solutions of sodium sulfate and hydrogen dioxid, which in its turn is 
1 See Kirk, American Text-book of Operative Dentistry. 



390 GANGRENE OF THE PULP. 

decomposed into water and oxygen, the latter driving out the altered 
contents of the tubuli. Any sodium oxid present is transformed by the 
sulfuric acid into sodium sulfate and water. The evidence of thorough 
action of the sodium dioxid is the bleaching of the dentin ; dentinal 
walls unbleached are evidence of incomplete action of the sodium 
compound. 

It has been advised by many operators that such canals be immedi- 
ately and permanently filled, as, indeed, they may be in very many cases, 
and no subsequent trouble arise. It is the part of prudence, however, 
to fill the canals temporarily until it is seen that no infection of the peri- 
cementum has occurred. During the period of probation, the canals 
are to be filled with a diffusible antiseptic ; oil of cassia is the agent 
most frequently and acceptably used for this purpose. Salol makes an 
excellent tentative filling in such cases ; it is combined with one-third 
its volume of aristol for this purpose. It is melted and flowed into 
the canals by means of Flagg's dressing-pliers, and while fluid a 
hot cOne of metal is thrust into the fluid mass. The canal-filling 
may be made of cotton-thread dipped in an antiseptic oil, if pre- 
ferred. 

In a few days, or, better, a week, if no evidences of pericemental 
disturbance appear, in excess of a slight and transient soreness, the tooth 
may be opened, always under rubber-dam, the canals cleansed, dried, 
and permanently filled. It is always a wise precaution to place 25 per 
cent, pyrozone in such canals for five minutes or longer before drying 
and filling the canals. Slight pericementitis, evidenced by tenderness 
of the tooth upon percussion, may immediately follow the treatment of 
canals by the sodium compounds, caused by the passage of a minute 
portion of the preparation beyond the apical foramen. As a rule, the 
irritation is but transient, and is soon reduced by applications of a 
counter-irritant upon the gum of the affected tooth — tr. iodin, tr. 
aconite, and chloroform, in equal parts, painted on the gum. More 
severe reactions indicate active pericementitis. 

Canals containing putrescible material which are too fine to admit 
even slender broaches are, after the action of the formalin solution, en- 
tered and cleansed bv means of the sulfuric acid method. Enlargement 
of the canals and destruction of the putrefactive matter are accomplished 
simultaneously. 

It has been maintained that if the pulp-canals could be lined with, 
and the contents of the dentinal tubuli be transformed into, permanently 
antiseptic material, that future sepsis would be rendered impossible. 1 
L. P. Bethel, 2 basing his procedures upon the fact that dentin impregnated 

1 Proc. American Dental Association, 1896. 

2 Proc. New York Institute of Stomatology, 1897. 



TREATMENT OF MOIST GANGRENE OF PULP. 



391 



with silver nit-rate notably resisted or prevented the progress of dental 
caries, conceived that if the same agent could be made to permeate the 
dentin of tooth-roots, it would act there as a permanent antiseptic and 
prevent future putrefaction and bacterial development. The tooth is 
isolated ; the application is confined to posterior teeth ; the danger of 
dentinal discoloration through the reduction of the silver salt is too 
great in the anterior teeth, and is only designed for canals of such size 
and shape that mechanical cleansing and filling are extremely difficult. 
The crown-cavity is to have its walls covered with wax or varnish to pre- 
vent the passage of the silver nitrate into the crown-dentin ; the canal is 
pumped full of a silver-nitrate solution (25 per cent, to 75 per cent.), a 
pellet of cotton containing the same solution is wrapped around the 
positive electrode of a cataphoresis apparatus, the current is applied, 
and the silver solution is driven into all of the tortuosities of the canal 
(Fig. 306). The silver combines with the contents of the dentinal tub- 



Fig. 306. 
4 5 




1. Operated on in the mouth with a 50 per cent, solution silver nitrate. Crown-cavity protected 

from discoloration by a thin coating of melted wax. 

2. Operated on in the mouth with a 75 per cent, solution silver nitrate. Crown-cavity protected 

with wax. 

3. Operated on in the mouth with 75 per cent, solution silver nitrate. 

4. Shows perfect lining formed, and penetration of the silver nitrate into the dentinal tubuli. 

5. Freshly extracted tooth operated on outside the mouth. The crown and roots were filled with 

decomposing material which was not removed, the electrode and nitrate being applied to the 
surface ; still the nitrate permeated the canals. Exposed surfaces of both canals shown. 

6. Operated on outside of mouth. Foramen on inside of root. 

7. Shows penetration in flat root with restricted and branching root-canal. Could not get broach 

more than one-eighth inch into canal. 
8 Operated on outside of mouth, for twelve minutes, attempting to force the silver nitrate through 

foramen of root. 
9. Shows returning branch of canal that might easily be left unfilled. 

uli, forming silver albuminate ; the nitric acid is formed at the posi- 
tive pole (the electrode), giving an acid reaction to the canal-contents ; 
the acid is neutralized with ammonia. Unless a very high voltage be 
applied, the silver does not penetrate the dentin to any considerable 
depth and it is not desired to have it do so. Crede's experiments 
indicate that metallic silver acts as an antiseptic by being oxidized 
by bacterial products, the argentic oxid being afterward transformed 
into antiseptic salts of silver by bacterial waste-products, notably by 
lactic acid, silver lactate being formed. 



SECTION V. 

DISEASES OF THE PERICEMENTUM. 



CHAPTEE XXI. 

SEPTIC APICAL PERICEMENTITIS (ACUTE). 

Classification. — The dental periosteum and ligament, or the peri- 
cementum, is the seat of numerous nutritive and functional disturbances, 
which may be grouped according to their causes into septic and non- 
septic. 

The term pericementitis has been indiscriminately applied to all 
affections of the pericementum, and in some cases erroneously, for in 
not all affections of this structure do the phenomena of inflammation 
appear. However, most of the acute and chronic degenerations are 
accompanied by evidences of inflammation. 

Bodecker's division of the affections of the pericementum into puru- 
lent and non-purulent is misleading. Cases may be due to septic 
causes without pus-formation ; pus-formation represents but one form 
of sepsis. 

The most convenient clinical classification of these disorders is that 
offered by G. V. Black i 1 first, diseases of the pericementum beginning 
at the apex of the root ; secondly, those beginning at the gum -margin ; 
thirdly, those beginning in some intermediate portion of the pericemen- 
tum. These may again be divided, according to their causes, into septic 
and non-septic. Another clinical classification would be into localized 
and general disturbances — another into acute and chronic. 

Evidences of Pericemental Disturbance. — It was noted in the study 
of the diseases of the dental pulp that the diagnostic signs of pulp-dis- 
turbance were exaggerated or diminished response to thermal stimuli ; 
reflected instead of localized pains ; and, except in rare cases of advanced 
degeneration, no tenderness upon percussion. Disturbances of the peri- 
cementum are accompanied by entirely different symptoms which serve 
to distinguish between them and diseases of the pulp. They are, in 
general, tenderness upon percussion. As shown by Black, 2 the peri- 

1 American System of Dentistry, vol. i. 2 Ibid. 

393 



394 SEPTIC APICAL PERICEMENTITIS. 

cementum is the touch-organ of the tooth, its tactile organ, through 
which a tooth locates force applied to the tooth. The pains of peri- 
cemental disturbance are, therefore, in the majority of cases, exactly 
localized, instead of not being localized as in the case of the pulp. 
A tooth tender upon percussion has its pericementum the seat of 
disturbance. Most cases of pericemental diseases are accompanied 
by vascular reactions ranging from an increased blood-flow or grades 
of hyperemia, to pronounced inflammation, and have the correspond- 
ing symptoms. The increased volume of the pericementum causes 
the protrusion and loosening of the tooth, heightened sensitivity being 
the accompaniment. As the vascular supply of the pericementum 
and that of the gum are in a degree collateral (see Chapter VIII.), 
evidences of vascular engorgement are seen in the gum overlying the 
affected tooth. Owing to the altered density of the parts surrounding 
the tooth-root, percussion upon the tooth elicits a different sound from 
that observed in health — the sound is dull. The general symptoms 
of pericemental affections are, therefore, tenderness upon percussion 
and a dull percussion-note, more or less protrusion and looseness of the 
tooth, and a deepening of the local gum color. 

Diseases of the Pericementum beginning at the Apex. 

Diseases of the pericementum beginning at the apex of the root are 
of two classes, septic and non-septic. The septic cases are almost in- 
variably the sequel to disease of the pulp, namely suppuration and 
gangrene ; or arise in consequence of infection through the canals of pulp- 
less teeth. The non-septic cases are due to mechanical and chemical 
irritants, and in rare cases to undiscovered causes. 

ACUTE SEPTIC APICAL PERICEMENTITIS — ACUTE ALVEOLO-DENTAL 

ABSCESS. 

Definition. — By septic apical pericementitis is meant a condition due 
to the entrance and the multiplication of septic organisms in the apical 
pericementum. The condition may be acute or chronic, the chronic 
cases being usually a sequel to an acute septic pericementitis. 

Causes. — By far the most common cause is infection of the peri- 
cementum, in the last stages of pulp-putrefaction, by pyogenic organisms. 
In the last stages of pulp-destruction through septic processes, it is usual 
to find that evidences of pericementitis exist : the tooth is tender upon 
percussion, is loosened, and protrudes slightly. As a rule, this irrita- 
tion subsides after a few r days. Succeeding this, is a period of quiet, 
before pronounced septic pericementitis arises. It appears as though 
the waste-products of the bacteria in the decomposing pulp acted as 
irritants upon the apical pericementum, and that by the formation of a 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 395 

barrier of new tissue the pericementum was temporarily protected. Its 
causes are found in all of the conditions under which moist gangrene of 
the pulp occurs. 

Purulent apical pericementitis is not always preceded by pulp-death 
and putrefaction ; although when the condition arises the pulp, if alive, 
dies. Considerable purulent destruction of the pericementum may occur 
near the apex of the root and the pulp of the tooth remain alive. The 
path of infection in these cases is unknown ; it is probably identical 
with that of pulp-putrefaction in cases without existing or previous 
caries. The possibility of infection by deposition of pyogenic organ- 
isms which have found their way into the circulation from other parts 
of the body must be admitted. The common infective organisms, those 
which predominate in purulent apical pericementitis, are the pyogenic 
staphylococci. Schreier l stated that out of twenty cases he had found 
in fifteen a diplococcus which he termed the diplococcus pneumoniae. 
Miller's 2 experiments failed to confirm the identity of the diplococcus 
found with that of pneumonia. Schreier' s studies 3 exhibit a prepon- 
derance of the staphylococcus pyogenes albus and aureus, diplococci, 
and occasional streptococci, virtually the same organisms that are found 
in the deeper portions of a suppurating pulp : this fact in itself is 
enough to show the continuity of infection from the pulp-canal. It is 
a well-known clinical fact that acute outbreaks of septic apical peri- 
cementitis are most liable to occur under those conditions when patients 
" take cold." Schreier points out that these atmospheric states produce 
a bodily condition which favors the development of the diplococcus 
pneumoniae, and finds in the association of these factors the reason 
why this diplococcus should be pathogenic in the dental condi- 
tion. 

Morbid Anatomy and Pathology. — The general morbid anatomy 
of this condition is that of abscess, modified, of course, by the anatom- 
ical structure of the part. * Pyogenic organisms gain access to the peri- 
cementum through the paths named, and a degree of inflammation is 
excited, governed by the virulence of the infection and the condition 
of the patient. An abundant, fibrinous, coagulable exudation is poured 
out into the interstices of the pericementum, not beneath the membrane 
— an exudation of leucocytes occurs ; the pericementum swells, its fibres 
at and about the apex soften, the fixed cells of the tissue undergo prolif- 
eration, and the tooth is protruded and loosened. The inflammatory cor- 
puscles are killed in great numbers by the waste-products of the organ- 
isms; the exudation is peptonized — liquefied by ferments excreted by the 
bacteria, the dead corpuscles being also broken down into a granular 
detritus. The inflammatory process extends radially from the focus of 
1 Dental Cosmos, 1893. 2 Ibid., 1894. 3 Ibid. 



396 



SEPTIC APICAL PERICEMENTITIS. 



infection, an inflammatory zone preceding the death and disorganization 
of corpuscles and effusions. The destruction of tissue proceeds in all 
directions, advancing most rapidly in the direction of least resistance, 
until the abscess reaches the surface, points, and discharges its contents. 
From the pericementum the inflammation extends to the alveolar bone, 
which is melted down molecularly ; thence to the periosteum, which 
undergoes inflammatory degeneration ; the gum-tissue is next involved, 

Fig. 307. 





Showing the morbid anatomy of septic apical pericementitis (acute): A, pus; B, area of dying 
leucocytes ; C, foreign matter in root-canal ; D, excavation of process (osteomyelitis) ; E, 
swollen periosteum and gum ; F, alveolar hone ; G, pericementum at edge of necrosis. 

until it is softened and perforated. While in the vast majority of cases 
the direction taken by the pus and the point at which it finds exit is 
the buccal or labial aspect, and immediately over the root-apex of the 
affected tooth, or near it, these being the directions of least resistance, 
other anatomical conditions or histological peculiarities (see Chapter 
VIII.) may make the direction of least resistance in some other 
path. 

Instead of the circumscribed suppuration described as the ordinary 
course of abscess-formation about the apices of roots (septic apical peri- 
cementitis) which accompanies infection by the staphylococci, clinical 
evidences of infection by a streptococcus occasionally appear. The 
inflammatory process, instead of being circumscribed, is diffuse ; the 
inflammation extends along the lines of connective tissues and of 
lymphatics ; the connective tissues are swollen, the swelling extending 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 397 

to the tissues of the cheek, down the neck, and even to the shoulder — 
. a phlegmonous inflammation. Instead of the comparatively free flow of 
pus which follows incision of the swelling in ordinary abscess, pus-for- 
mation in streptococcus infection is seen, upon incision, to be limited and 
sero-purulent. While in alveolar abscess of the ordinary types evidences 
of septic intoxication or poisoning are unusual, the lymphatics being 
blocked, as a rule, by the inflammatory exudation ; septic intoxication 
and poisoning are the rule in the erysipelatous cases, those probably 
due to streptococcus infection ; bacterial poisons being taken up by the 
lymphatics find their way into the circulation. 

After spontaneous discharge of the pus from an abscess, the 
condition remaining is that of an ulcerous surface (the abscess boun- 
daries), which is being continuously infected from the putrescent pulp- 
remnants. The conditions, it is seen, are not like those of ordinary 
abscess, where the infective material is largely discharged in the pus- 
evacuation, and the cells bounding the abscess-wall dispose of remain- 
ing bacteria, so that regeneration of tissue occurs. Spontaneous healing 
of an alveolar abscess is the exception ; the embryonic tissue lining the 
abscess-walls being continuously infected, degenerates and dies instead of 
regenerating, leaving a condition known as chronic alveolar abscess, or 
chronic apical septic pericementitis purulenta. 

Symptoms. — According to the severity of the symptoms, apical 
pericementitis may be divided into several grades, each of which repre- 
sents more or less well-defined pathological conditions. It is to be 
remembered that the normal progress and outcome of this condition 
are toward the formation and evacuation of pus, so that the symptoms 
will be largely governed by the difficulty or readiness with which 
the discharge is effected. Infection represents the first stage of the 
acute disease, pus-discharge the last, after which the acute symptoms 
subside. 

The first symptom to appear is tenderness upon percussion, the dis- 
ease being ushered in by an active hyperemia, As in other active 
hyperemias, the sensitivity of sensory nerve-fibres is heightened ; if 
the tooth be moderately pressed upon, it is tender ; but if forcibly 
pressed upon — i. e., the apical arteries be compressed — the hyperemia 
is momentarily lessened, and the pressure brings a sense of relief. 
This period is succeeded by a protrusion of the tooth beyond its fellows ; 
it appears to be, and is, longer than the other teeth ; it is loosened and 
becomes very sore upon pressure, and soon tender or exquisitely painful 
to the slightest touch. Throbbing pain now occurs, and the gum overlying 
the affected tooth, first heightened in color, becomes swollen and deeply 
colored. These conditions correspond with the exudation-period of tin 1 
inflammation. The tooth becomes progressively looser, and so tender 



398 SEPTIC APICAL PERICEMENTITIS. 

that it will not bear the slightest touch ; the throbbing pain increases 
in severity, and the gum-tissue, and, it may be, the tissue of the cheek 
or lip, also become much swollen. The swelling of the gum, at first 
of board-like hardness, softens at its highest point ; soon a yellow spot 
appears, the mucous membrane bursts, and a discharge of pus follows. 
As soon as softening of the swollen gum occurs the excruciating pain — 
an acute alveolar abscess is one of the most painful of diseases — and 
the tenderness of the affected tooth usually diminish, but some degree 
of protrusion and loosening remains. 

In multirooted teeth the inflammation and abscess frequently appear 
on only one root. If the case be seen early, before the active exudation- 
period of the inflammation sets in, the symptoms may be clearly localized 
in one root, the tooth exhibiting tenderness upon pressure over the affected 
root, but not upon the opposite side. 

The symptoms above described are those of average severity. 
Variations occur ; some cases have a lesser degree of intensity, some 
a higher degree. Pain and swelling may be comparatively slight 
and pus-discharge prompt. In other cases pain, swelling, and loose- 
ness of the tooth are pronounced at an early period, and several 
grades of constitutional disturbance may appear. The pulse increases 
in volume and tension, the tongue is coated, and the temperature 
of the body rises ; the rise of temperature may be ushered in with 
a distinct chill — i. e., a condition of fever is present, due to the 
absorption of bacterial products. As a rule, these general symptoms 
accompany the cases in which the vascular disturbance is widespread. 
Instead of the swelling extending but little beyond the overlying gum, 
the tissues of the lips, cheeks, or neck may be very much swollen and 
the eye of the affected side injected. In some cases the outer skin may 
become reddened and dusky, exhibiting the evidences of extension of 
the inflammatory process far from its original site. 

Clinical History. — As shown in Chapter VIII., the apices of the 
roots of teeth lie nearer to the external alveolar wall than to the inner, 
with the exception of the palatal roots of the upper molars and the 
roots of the lower molars, the ends of the roots in some cases being 
covered by laminae of bone of extreme thinness. Apparently the 
alveolar periosteum and gum-tissue vary in density. Recognizing these 
differences, the clinical history of acute alveolar abscess mav be divided 
into three stages : first, that of initial inflammation and pus-formation ; 
secondly, the destruction of the alveolar process ; thirdly, the passage 
of pus through the periosteum and mucous membrane. The second 
stage is usually the longest. The duration of the disease depends upon 
the readiness with which the tissues between the point of beginning pus- 
formation and its exit yield. When the pulp-chamber is open pus may 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 399 



Fig. 308. 



find exit by this path, constituting the condition known as blind abscess 
— a misnomer, because a blind abscess is one without a point of dis- 
charge, without a fistula leading to it ; 
in the cases discharging via the canal, 
the latter may be considered a fistula. 

These cases usually run a short 
course, the inflammatory symptoms 
rarely being severe, and the tissue-de- 
struction limited (Fig. 308). Notably 
upon lower molars, and upon the pa- 
latal roots of upper molars, the dens- 
ity and thickness of bone overlying 
the roots may make paths of greatly 
increased resistance, so that the de- 
struction of tissue proceeds along the 
line of the pericementum, the pus finding 
exit at the neck of the tooth (Fig. 310). 

It is rare in cases of lower second molar, and still more rare upon the 
third molars, that pus finds exit over the apex of the root, the .dense bone 
of the external oblique line (Fig. 309) offering the greatest resistance 




Blind abscess at the root of an upper 
incisor : o, abscess-cavity in bone ; b, 
drill-hole exposing the pulp-chamber 
for treatment. (Black.) 



Fig. 309. 



Fig. 310. 





Fig. 309— Abscess upon lower third molar, showing the usual paths of pus-exit, A and B. 
Fig. 310— Abscess upon palatal root of an upper molar discharging at the neck of the tooth. 

Over any teeth the outer fibrous layers of the external periosteum 
may offer unusual resistance to the perforative advance of pus, so that 
when the fibres of attachment of the periosteum have been softened by 
the inflammation, and pus gains entrance between bone and periosteum, 
it may travel or burrow along the course of this membrane (Fig. 311), 
depriving the bone of its main nutritive source, so that limited necrosis 
threatens. The roots of the central incisors may lie unusually close to 
the floor of the nose, and be overlaid externally by an unusually resist- 
ant layer of bone ; in these cases the path of least resistance may be in 



400 



SEPTIC APICAL PERICEMENTITIS. 



the direction of the floor of the nose, the abscess opening at that point 
(Fig. 312). 



Fig. 311. 




Acute alveolar abscess of a lower incisor, with pus-cavity between the bone and the periosteum : 
a, pus-cavity in the bone; b, pus between the periosteum and bone; c, lip; d, tooth; e, 
tongue. (Black.) 

The root-apices of the posterior upper teeth, particularly of the first 
and second molars, may after the age of twenty-five or thirty be 

Fig. 313. 





Fig. 312.— Alveolar abscess at the root of a superior incisor discharging into the nose : a, large 
abscess-cavity in the bone ; b, mouth of fistula on the floor of nostril ; c, lip ; d, tooth. 
(Black.) 

Fig. 313.— Alveolar abscess at the root of an upper molar discharging into the antrum of High- 
more : a, abscess-cavity in the bone ; b, mouth of fistula on the floor of the antrum; c, pus in 
the antral cavity. (Black.) 

encroached upon by the enlarging maxillary sinus, so that any or all 
of the roots of these teeth may be separated from the floor of the sinus 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 401 

by but a very thin lamina of bone ; should abscess arise upon any of 
these roots, pus-discharge into the antrum would necessarily follow 
(Fig. 313). 

Resort to the use of poultices, for the relief of the pain of abscess- 
formation, may induce such a softening of the tissues over which they 
are applied, that the passage of pus is invited toward the exterior ; the 
abscess may thus open upon the face or neck, producing permanent, 
disfiguring scars. 

In patients who are in a cachectic condition, who have an evil 
heredity, or whose tissue-resistance is markedly lessened in consequence 
of tuberculosis, or more frequently of syphilis, septic pericementitis 
may run a riotous course ; the bone suffers extensively by direct action ; 
the periosteum is undermined, is stripped from the bone over large areas, 
and breaks down readily ; so that while in the healthy person alveolar 
abscess-formation may run a direct course and find prompt outlet, in 
the syphilitic patient extensive pus-infiltration, with necrosis, may occur. 
In cachectic persons lymphatic involvement is common ; waste-products 
of bacterial origin find their way into the lymphatics and set up sec- 
ondary irritative processes in the nearest lymphatic glands — lymph- 
adenitis. 

In persons whose oral hygiene is neglected the third stage of alveolar 
abscess is frequently violent and the inflammatory process widespread. 

In acute abscess-formation the inflammatory action precedes the 
advance of pus, which furnishes a guide to the direction the pus is 
pursuing ; viz., where the most intense coloration and the greatest swell- 
ing appear will be the point at which the abscess will point or discharge. 
A subsidence of inflammation without an immediately discoverable 
point of pus-exit should lead to the suspicion that the discharge has 
taken place in an unusual situation. 

Diagnosis. — If a tooth have been the seat of acute septic pericemen- 
titis of high grade for twenty-four hours, pus has almost certainly 
formed, and its presence may be safely diagnosed. The symptoms 
rarely leave any doubt as to which tooth is affected, except where two 
contiguous teeth, evidently pulpless, are both loosened and surrounded 
by a zone of inflammation. Even in these cases there will be found 
differences in response to tapping or pressure which will indicate which 
tooth is the disease-focus. 

Prognosis. — In the majority of cases the prognosis of acute alveolar 
abscess, as to the future retention of the tooth, is favorable ; and usually 
very favorable, if the case receive intelligent therapeutic aid. The 
future of the tooth depends upon the thoroughness with which sources 
of infection may be destroyed and permanently removed, and the com- 
pleteness with which regeneration of tissue can be induced. 

26 



402 SEPTIC APICAL PERICEMENTITIS. 

If the first stage of abscess-formation be prolonged, destruction of 
pericementum is correspondingly increased ; a prolonged second stage 
causes an increased molecular destruction of alveolar bone ; a prolonged 
third stage may mean stripping of the periosteum from the alveolar 
wall, or infiltration of pus into the connective tissue of the lip or 
cheek. Marked swelling of the tissues of the face, with an increasing 
redness of surface, leads to the suspicion of pus-presence and the danger 
of its external discharge. Rigors and fever, appearing during the course 
of the inflammation, are evidence of absorption of and the presence in 
the circulating fluids of bacterial products. Repeated rigors, with pro- 
nounced depression, diarrhoea, and delirium, indicate that pyaemia 
exists. Delay in the natural evacuation of the pus should lead to the 
suspicion that it is pursuing an unusual course, its direction being 
usually determined by the focus of inflammatory action. 

Treatment. — The first principle of treatment is the removal of the 
source of infection. As in all other septic diseases, there is no means com- 
parable with this in point of effectiveness. After removing the source 
of infection the symptoms of the disease-process subside rapidly. If it be 
not removed surgically, the disease persists until the pus finds vent, when 
the inflammation subsides. The immediate accomplishment of this end 
may, however, be impracticable in some cases. Recognizing the putres- 
cent pulp-canal contents as the source of infection, primary attention 
is, of course, directed toward sterilization and removal of these con- 
tents. If the case be seen before the inflammatory process become pro- 
nounced, entrance to and cleansing of the canals can usually be accom- 
plished. If the pulp-cavity be open in such cases, direct approach is 
made to the canals through the carious cavity. A free syringing with 
strong solutions of meditrina precedes the opening of the canals. If it 
be a filled tooth, and the filling is in a situation that by an opening made 
through it, or by its removal, direct access to the canals can be gained, the 
opening should be made. The opening of the cavity is to be accomplished 
by means of a very sharp and small spear-point drill revolving in a per- 
fectly true hand-piece. Large drills, ill-sharpened and in worn hand- 
pieces, produce a jarring which adds notably to the tenderness of the 
pericementum. According to the amount of tenderness, the tooth will 
require a counter-pressure to that of the drill. If the entrance be 
made through the occlusal face of the tooth, or in a direction which 
would cause direct upward pressure on the apical pericementum, a liga- 
ture of linen thread with long ends may be placed around the tooth, 1 
and traction be made by drawing on the loose ends of the ligature. 
Effective counter-pressure against lateral entrance to the pulp-chamber 
may be made by softening a small roll of modelling compound and 
1 «L Foster Flagg, Lectures on Dental Therapeutics. 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 403 

moulding over the face of the affected tooth and several of those adjoin- 
ing it, and permitting it to harden. This temporary splint is held in 
place by the index finger of the left hand. In case the inflammatory 
process is marked, it is frequently necessary to make a vent-opening by 
the most direct path — i. e., at the junction of enamel and cementum — 
directly into the chamber. 

As soon as entrance to the pulp-chamber is effected, the cavity is 
syringed with a strong antiseptic ; a 20 per cent, solution of meditrina 
answers well in this connection. Fine probes are passed and repassed 
into the opening to free the outlet, so that gases may escape and fresh 
portions of the antiseptic be worked into the cavity. The quickness 
with which relief is secured will depend upon the thoroughness with 
which the canals are entered and their putrid contents destroyed. A 
tedious class of cases are those in which a canal of a molar is unfilled or 
but partially filled. Unless entrance to and cleansing of the canal be 
accomplished, the inflammation will proceed until the pus finds external 
vent. An hour spent in gaining access to and cleansing such canals is 
well spent. 

If entrance to the canals is free, repeated applications of sodium 
dioxid solutions should be made, pumped into the canals, and the cavity 
Avashed from time to time with meditrina or hydrogen dioxid. Near 
the end of the canal the meditrina is used alone with broaches, and 
finally by syringing. The canals are dried, and an anodyne antiseptic, 
such as a mixture of thymol and menthol dissolved in glycerin, is 
pumped into the canals. If now provision for surgical rest of the 
irritated pericementum be made, relief is tolerably certain. A moldine 
impression is taken of the adjoining tooth, if a bicuspid or a molar, or 
of one the bicuspids, if a labial tooth be the one affected, and a fusible 
metal die is made. Driven into a block of soft lead, a counter-die is 
formed and a metal cap to cover the occlusal and part of the buccal and 
lingual surface of the tooth may be swaged in a few moments. About 
No. 26, American gauge, should be the thickness of the metal. The 
tooth is dried and the cap attached by means of zinc phosphate, and 
allowed to remain for a day or two. This will insure rest of the 
affected pericementum. If now the gum, at a distance from the tooth, 
be painted with tr. .iodin and chloroform as a counter-irritant, the 
inflammation usually subsides and almost disappears in a couple of 
days. These several measures are to be regarded as the abortive treat- 
ment of alveolar abscess ; they apply to all cases if seen early enough, 
and will in the majority of cases prevent the disease of the peri- 
cementum passing the early inflammatory stages. In all cases the 
severity of the inflammatory process is lessened in proportion to the 
thoroughness with which the antiseptic measures are applied. 



404 SEPTIC APICAL PERICEMENTITIS. 

i 

If the case be a more severe one, or at a later stage than that 
described, the excessive tenderness of the tooth may preclude any 
attempt at drilling into the pulp-chamber without the administration 
of a general anaesthetic. When the cause, clinical history, and indicated 
therapeutics in alveolar abscess, are viewed, there can be no two opinions 
as to the wisdom of anaesthetizing the patient and effecting an entrance 
to the pulp-canals. It cannot be too strongly emphasized that canal- 
sterilization is in order at any stage of abscess-formation, as is also the 
free and frequent use of antiseptic mouth -washes — pyrozone and medi- 
trina. Failing to administer a general anaesthetic, the canals are opened 
as freely as the tenderness of the tooth permits ; the use of any instru- 
ments, except broaches applied with the utmost delicacy of touch, is 
precluded by the intolerable pain. An effort is made to limit the extent 
of inflammatory action. After the early stages and up to nearly the 
point of pus-perforation, hot applications in the mouth and the use of 
counter-irritants to the gum but provoke the inflammatory condition. 
The most effective measure is local bloodletting by means of a leech, 
if possible, or by making several free cuts with a bistoury, which tend 
to relieve the engorged vessels of the pericementum. The mouth should 
be washed with warm antiseptics before and after the incisions. Dry 
cups to the back of the neck and hot mustard foot-baths are also useful 
derivative measures. 

In the still more severe cases marked relief of the inflammatory 
symptoms and the pain follows the administration of 10 gr. of Dover's 
powder, in addition to the measures advised. A saline cathartic, mag- 
nesium sulfate, should be administered the next morning, with a view to 
relieving the constipation following the use of the opium, and to act 
as a derivative by inducing free watery stools. 

If high inflammation persist for more than twenty-four hours, pus 
is almost certainly present in the pericementum, and possibly more or 
less molecular destruction of bone has occurred. In rare cases, where the 
bone-covering of the root-apex is extremely thin, the pus may be at this 
time at the point of exit. The dictum of surgery, to give vent to pus as 
soon as it is discovered, applies as well in the condition under discussion 
as anywhere else. When it is considered that prior to evacuation of the 
abscess destruction of tissue is going on in all directions, it is evident 
that tissue-destruction, complications, and the possibility of septic intox- 
ication, or even more serious general disturbances, will be averted by 
gaining quick access to the focus of infection and removing it. Some 
operators advise that an artificial opening be made even in the earlier 
stages of acute septic pericementitis, recognizing that the case is septic 
and that radical relief is only secured through complete antisepsis. If 
the case be seen early, however, the abortive measures previously de- 



DISEASES OF PERICEMENTUM BEGINNING AT THE APEX. 405 

scribed can be instituted. The old practice of waiting until the pus has 
penetrated the alveolar periosteum is unsurgical. 

To insure quiet of the patient while opening into the apical space 
from the gum, it is advisable to administer nitrous oxid, if this agent 
be available. The mouth should be freely washed with strong anti- 
septics and a cut made through the gum over the apex of the affected 
root. The incision is permitted to bleed, and is then packed with 
cotton containing phenol sodique. As soon as bleeding has ceased 
the nitrous oxid is administered ; if it be not at hand, a pellet of cotton 
containing a 10 per cent, solution of cocain is laid against the periosteum. 
The first cut, made with a stout-pointed bistoury, penetrates to the bone. 
A sharp scaler or chisel is used to scrape away a small area of the 
alveolar periosteum ; next a spear-pointed drill, revolving rapidly, is 
quickly passed through the outer alveolar plate into the apical space. 
The apices of the roots lie, as a rule, slightly higher than the line 
of mucous membrane reflection. The cut should be free and the peri- 
osteum scraped away, to avoid annoying and disfiguring emphysema of 
the cheek-tissues, which may occur if these precautions be not taken. 
The pain following the operation may be relieved, after bleeding has 
ceased and the cavity has been washed out with warm antiseptics, by 
pushing a crystal of cocain hydrochlorid into the cavity as far as it will 
go. As soon as the inflammatory symptoms have subsided sufficiently 
to permit working upon the tooth, the pulp-canals are to be opened and 
sterilized. 

The case may not be seen until its third stage, when the pus is in 
the tissues exterior to the alveolar process. In these cases a very sharp 
bistoury is passed into the swelling at its most prominent part and a deep 
and free incision made. In case the inflammation have extended to the 
tissues of the cheek, an outcome most to be feared in abscess upon the 
lower third molar or upon the upper first or second molar, antiphlo- 
gistics should be applied to the cheek — 

]^. Plumbi acetat., sj ; 

Tr. opii, Ij ; 

Aquae, Oj. — M. 

Compresses wet with this preparation are laid upon the cheek, and a 
free, deep incision made in the gum at the junction with the cheek. 
An examination should always be made of the palatal and lingual alve- 
olar aspects, to note whether the inflammatory and suppurative process 
tends to take either of those directions. 

If, in connection with the lower third molar, marked swelling is ob- 
served in the submaxillarv triangle, free incision of the tissues of the 



406 SEPTIC APICAL PERICEMENTITIS. 

floor of the mouth should be made at the angle of junction with the 
bone. The cut should be made close to the bone and into it, but not 
too deep, lest the mylohyoid artery or nerve be injured. In all cases 
which threaten to open externally the antiphlogistic compresses are to 
be continuously applied externally, and after incision stimulant mouth- 
washes should be used ; that recommended by Prof. Garretson is excel- 
lent — tr. myrrhae et capsici in water. 

It is ever to be borne in mind that so long as the source of infection 
remains pus-formation continues, and so long as pus forms, tissue-de- 
struction is in progress ; furthermore, in proportion to the amount of 
tissue-loss perfect recovery after alveolar abscess is delayed or imperfect. 

While it is the clinical experience of nearly every operator that a 
tooth and adjacent structures may recover from inflammation which 
involves not only the first tooth attacked, but by an extension of the 
inflammatory process involves the general periosteum and neighboring 
teeth, provided the case receive prompt and decisive surgical treatment, 
yet the danger of septicaemia in prolonged cases is always imminent. 
When the general periosteum is involved, as shown by extensive boggy 
swelling in the mouth, if several free incisions carried to the bone do 
not afford prompt relief, the tooth which is the centre of infection should 
be promptly extracted. If, in the course of the pericementitis, chills, 
followed by fever, a coated tongue, and much physical depression occur, 
a general infection is to be feared, and no time should be lost in steriliz- 
ing the mouth, extracting the tooth, and subjecting the socket to free 
spraying with antiseptics. 



CHAPTER XXII. 
SEPTIC APICAL PERICEMENTITIS (CHRONIC). 

Chronic septic apical pericementitis exhibits several grades as to 
its extent and effects ; one of the more pronounced types or grades 
being the direct outcome of acute apical pericementitis, resulting in pus- 
formation, a condition known as chronic alveolar abscess. After the 
discharge of pus, either spontaneously or through surgical aid, as noted 
in the discussion of acute alveolo-dental abscess, the source of infection 
remains, and pus-formation continues as a chronic process, which rarely 
disappears spontaneously ; the acute inflammatory symptoms, however, 
subside and do not reappear unless there is some interference with the 
escape of the pus. 

Clinically chronic abscess presents itself in two classes : cases with- 
out a fistula communicating with the mouth-cavity or other part, and 
those in which the pus finds vent through a fistula. 

Chronic Alveolo-dental Abscess without Fistula. 

Pathology and Morbid Anatomy. — Although the acute inflamma- 
tory symptoms may subside and be replaced by those of atonic hyper- 
emia, as soon as pus finds vent through the canal of the tooth ; 
pus-formation — i. e., tissue-destruction — proceeds radially from the 
affected root. The conditions existing immediately after evacuation 
of the pus are a denuded root-apex, about which are peptonized 
(liquefied) effusions, in which are shreds of dead tissue, and dead, dying, 
and disintegrated inflammatory corpuscles, occupying a cavity bounded 
by embryonic tissue, which is being gradually invaded by pyogenic 
organisms ; the surrounding tissue is being transformed into or replaced 
by embryonic tissue, the result of inflammatory degeneration. The cavity 
bounded by this wall of embryonic tissue is constantly increasing in 
size. In long-continued cases organization of the boundary -wall may 
occur, and the cavity be enclosed by a capsule of vascular fibrous con- 
nective tissue. If teeth be extracted at this stage, this fibrous sac may 
come away with the tooth ; it is the structure sometimes termed a pyo- 
genic membrane. 

The influence of gravity has much to do with the direction of 

407 



408 



SEPTIC APICAL PERICEMENTITIS. 



tissue-destruction in chronic abscess (Figs. 314 and 315). In the lower 
jaw the tendency is to burrow into the cancellated tissue of the bone 



Fig. 315. 



Fig. 314. 





Fig. 316. 



Fig. 314.— Chronic blind abscess of upper incisor, showing tendency of pus to progressively destroy 
pericementum owing to the influence of gravity. 

Fig. 315.— Chronic blind abscess upon lower tooth, showing tendency of pus to sink into the sub- 
stance of the lower maxilla, owing to the influence of gravity. 

away from the tooth, so that destruction of the pericementum may not 
be very extensive. In the upper jaw the tendency is to spread along 

the pericementum and into the cancellated 
bone, so that the cavities of chronic abscess 
upon the upper anterior teeth particularly may 
cause extensive excavation in the palatal pro- 
cess of the superior maxillary bone (Fig. 316). 
The pus may burrow in irregular and circuitous 
directions, until it finds external vent. In long- 
established cases the denuded root-apex becomes 
the seat of calcic deposits. 

Symptoms and Diagnosis. — Attention is 
directed to some pulpless tooth or to a crownless 
root, around which the gum-color is deepened and which is more or less 
loose, indicating softening of its pericementum, but no fistula is present. 
After isolation under rubber-dam pus may or may not be discoverable 
in the canals. If pus is seen, the diagnosis is evident. If pus be not 
seen, and the canals be drenched with a 50 per cent, solution of sodium 
dioxid, the application being continued until it is reasonably certain that 
all infective material in the canals has been destroyed, the canals may 
be closed with the dressing usual in such cases, twists of cotton sat- 
urated with an antiseptic oil, when irritation should be allayed if an 




CHRONIC ALVEOLO-DENTAL ABSCESS WITHOUT FISTULA. 409 

abscess does not exist ; but if, after some hours, or a day or two, in- 
flammatory symptoms arise, the presence of pus should be suspected, 
and its existence may be confirmed by its flow upon removing the 
canal-dressing. More or less pus should always be suspected about the 
roots of teeth which are crownless or pulpless, and have unfilled canals, 
when the tooth is loose, and the overlying gum injected. In doubtful 
cases canal-fillings, even after thorough cleansing with sodium dioxid, 
are made of an easily removable material, and are only made tentatively 
until it is certain that a tightening of the pericementum and a fading of 
the deepened gum-color, instead of an increased irritation, follow their 
insertion. 

Prognosis. — The fate of the affected root depends upon the amount 
of tissue-destruction, the length of time suppuration has been going on, 
and the recuperative powers of the patient's tissues, together with — 
most important of all — the thoroughness with which infection and the 
sources of infection are removed. If the last-named object can be at- 
tained, astonishing recoveries occur ; in its absence, the tooth is certain to 
be permanently crippled and to be a menace to the surrounding tis- 
sues. It is remarkable, however, how long pus-formation may con- 
tinue about the root of a tooth, and cause comparatively little disturb- 
ance, except in a very circumscribed field. The presence of pus in 
any cavity of the body should never be regarded as without danger ; 
and, doubtless, constitutional effects from pus-formation about the 
teeth are often present without the operator being cognizant of 
them. 

Treatment. — The principle of treatment is to remove all pus, dead 
tissue, and infective organisms, induce a regeneration of tissue to obliter- 
ate the abscess-cavity, and prevent future infection. The heroic and 
most successful method of treatment is to remove, as a primary meas- 
ure, the mechanical impediment to the thorough washing and sterilizing 
of the abscess-cavity. So long as the entrance to the abscess-cavity and 
the exit from it are but the constricted passage of a root-canal, it is 
evident that the complete filling and emptying of the abscess-cavity will 
be attended with difficulty, depending upon the size of the canal and 
of the abscess-cavity. If, however, an external fistula exist, the com- 
plete washing of the tract and emptying of the cavity are much facilitated ; 
abscess with external fistula is much more amenable to treatment than 
when no such exit exists. The tendency of modern practice, there- 
fore, is to establish a free artificial fistula in all cases of so-called blind 
abscess 

The canals are cleansed with sodium dioxid solution, and the canal 
length and direction recorded upon a broach. This length is measured 
upon the gum to determine the point of entrance. The most certain 



410 



SEPTIC APICAL PERICEMENTITIS. 



and quickest method of making the proper entrance is to administer 



nitrous oxid, or, if that be not 



Fig. 317. 

O O O 



Fig. 318. 




4 6 5 

Tubular knives. 



Walker-Younger trephines. 



available, to inject a few drops 
of a boiled solution (10 per cent.) 
of eucain into the gum and re- 
move a cylindrical portion of 
gum-tissue by means of a Rollings 
tubular knife, or make an incision 
to the bone and scrape off a por- 
tion of periosteum ; entrance to 
the abscess-cavity may then be 
made by means of a drill or small 
trephine (Fig. 318). The case is 
now treated as one of abscess with 
fistula (which see). 

Cases may be treated without 
making an artificial fistula, but the results are rarely so satisfactory and 
the cure seldom so complete as when an artificial opening is made. The 
best results are obtained where the destruction of tissue has been very 
limited, w T here the pus has found exit through the canal at an early 
period, and Avhere the case is seen soon after subsidence of the active 
inflammation. 

The tooth-cavity is cleansed mechanically, syringing freely with 
meditrina or 3 per cent, pyrozone solution, and the rubber-dam adjusted. 
The canals are cleansed by repeated applications of sodium dioxid solu- 
tion, continued until the apex of the root is passed, when the canals are 
forcibly syringed with an acid solution of hydrogen dioxid until effer- 
vescence ceases. The canal is now thoroughly dried and filled with an 
antiseptic ; Black's 1-2-3 mixture, campho-phenique, oil of cassia, and 
thymol are all useful. If the canals have been well cleansed and the 
antiseptics employed have been carried into the abscess-cavity, further 
use of antiseptics is not absolutely necessary, but it is prudent to use 
them to complete a possibly partial sterilization. The antiseptic may 
be driven in spray into all portions of the abscess-cavity, by blowing a 
blast of air into the canal through a chip-blower. The canals are next 
partially dried and loosely filled with cotton, and the crown-cavity 
hermetically sealed. 

If in the course of two or three days, the tooth appears tighter and 
the vascular symptoms in the gum subside, a cure may be anticipated. 
As a precautionary measure, the tooth may be placed under rubber-dam, 
the seal and canal-filling removed, and the condition as regards odor and 
the presence of pus or blood-stains noted. If odor be present, a second 
cleansing with sodium dioxid should be practised as before, the canals 



CHRONIC ALVEOLO-DENTAL ABSCESS WITH FISTULA. 411 

dried, and a cotton twist saturated with thymol packed into them. If 
no symptoms arise, this dressing may remain a week or longer. At the 
expiration of this time the abscess-cavity is probably filled with organ- 
izing granulation-tissue. The canal may be opened under extraordinary 
antiseptic precautions and filled with melted paraffin and aristol, 
nosophen, euthymol, or iodoform. The crown-cavity may be filled with 
zinc phosphate, and the case be dismissed for six months or longer. If a 
gold filling is indicated, this time should elapse before it is inserted. 

If the tooth rebels against closing after more than one cleansing with 
sodium dioxid, it is scarcely worth while temporizing — an artificial 
fistula should be established. 

In rare instances a cure of even extensive suppuration, with large 
cavity, may be effected without an artificial fistula, by sterilizing the 
affected root, aspirating the pus, washing out the abscess-cavity, and 
inducing regeneration. The tooth should be isolated, its canals cleansed 
with sodium dioxid and washed. As deep into the canal as possible the 
nozzle of a large syringe is placed ; temporary stopping is packed into 
the crown-cavity tightly about the syringe ; the piston is withdrawn, 
drawing the pus into the syringe. The withdrawal may fail entirely 
owing to the apical foramen being blocked by shreds of dead tissue. 
If the attempt be successful, the stopping is removed, the canals dried, 
and a drop or two of a 25 per cent, solution of pyrozone pumped into 
the abscess-cavity, more being added until effervescence ceases. When 
the canals are dried they are filled with an antiseptic — thymol, campho- 
phenique, etc. — driven in spray into the abscess-cavity by blasts of warm 
air. If the evidences of disturbance subside, the case is treated as in 
the former instance. If the tooth rebel against closing, an artificial 
fistula should be established. 

Chronic Alveolo-dental Abscess with Fistula. 

Morbid Anatomy and Pathology. — The conditions found attend- 
ant upon this disease depend, first, upon the length of time elapsing 
between the inception of the inflammatory process and the evacuation 
of the abscess ; secondly, upon the surgical anatomy of the parts ; and, 
thirdly, upon the physical condition of the patient. In the majority of 
cases the pus from acute abscess finds exit almost immediately over 
the apex of the affected root, in the course of a few days, so that at 
this time a canal lined with embryonic connective tissue may connect 
with a cavity of any size lined with embryonic tissue, the walls of which 
continue in a state of infection. If the process continue, organization 
of the abscess-wall occurs as in abscess without fistula. 

Instead of finding exit by a direct path to the exterior, the pus may 
burrow along the length of the pericementum and discharge at the neck 



412 



SEPTIC APICAL PERICEMENTITIS. 



of the tooth. One-half or more of the lateral aspect of the pericemen- 
tum may remain vital, although involved in a chronic inflammation, 
the remainder being destroyed. Where the apices of the roots of upper 
posterior teeth lie in very close proximity to the floor of the antrum, 
perforation of this floor may occur before tissue-destruction has pro- 
ceeded far enough in other directions to afford escape to the pus. Ex- 
tensive pus-accumulations may occur in the antrum in consequence. 
Other paths of pus-exit are noted in Chapter XXI., in connection with 
acute abscess ; at such points the discharge may remain persistent. In 
some cases, after the subsidence of the acute inflammatory symptoms, 
pus-discharge may lessen and finally cease, the fistula healing, although 
pus-formation in the substance of the bone continues. The discharge 
only ceases, however, when the pus finds some other point of discharge ; 
usually this is through the canal of the affected tooth ; the condition 
then becomes one of blind abscess. The burrowing of the pus continues, 
however, and at a late period may find exit at a distant point. Upon 
a lower tooth, particularly the incisors, the pus may burrow downward 
through the cancellated tissue of the bone and emerge at the base of the 
bone and open upon the face (Figs. 319 and 320). 

In other cases the pus may perforate the bone, and find passage along 
the submuscular tissue of the depressor muscles of the lip, opening 

above or under the point of the chin. The 
apices of the roots of teeth lying beneath the 
line of insertion of the mylohyoid muscle 
may cause an abscess to open in the neck- 
cavity. Oyer records a case where an ab- 
scess opening upon the face immediately 
anterior to the line of the facial artery, 
was traced to the root of a lower molar ; 

Fig. 320. 



Fig. 319. 





Fig. 319.— Chronic alveolar abscess of the root of a lower incisor, with abscess-cavity passing through 
the body of the bone and discharging on the skin beneath the chin : a, very large abscess- 
cavity ; b, mouth of the fistula. (Black.) 

Fig. 320.— Fistula passing down through the body of the lower maxilla. (Black.) 



CHRONIC ALVEOLO-DENTAL ABSCESS WITH FISTULA. 



413 



Fig. 321. 



the direction of the sinus is shown in Fig. 322. In a case having a 

similar anatomical association, the pus 
penetrated the bone lingually, was en- 
capsuled beneath the internal pterygoid 
muscle, and appeared as a swelling at 
the inner aspect of the angle of the jaw. 
Occasionally the apices of the roots of 
lower molars are separated from the 
inferior dental canal by only a thin lam- 
ina of bone, so that discharge into this 

Fig. 322. 





Fig. 321.— Chronic alveolar abscess at the root of a lower incisor, with a fistula discharging on the 
face under the chin : a, abscess-cavity in the bone ; b, b, b, fistula following in the periosteum 
down to the lower margin of the body of the bone and discharging on the skin. (Black.) 

Fig. 322.— Abscess with tortuous sinus, opening upon the face : A, tissue of cheek ; B, floor of mouth ; 
C, abscess-tract. 

canal may occur with infiltration along the vessels and nerves in the 
canal. While discharge into the nasal chamber is most frequently asso- 
ciated with abscess upon the central incisors, abscess upon molars may 
discharge into the same cavity. 

Symptoms and Diagnosis. — The symptoms of the condition are a 
fistulous opening in the gum or some other part, in proximity to or con- 
nected with a pulpless tooth. The tooth may have an open cavity, con- 
tain a filling, bear an artificial crown, or be free from caries. In other 
cases, the root which is the centre of infection may lie buried in the gum 
and be invisible. The source of the trouble in rare cases may be an 
impacted tooth (see Chapter X.). As a rule, the seat of the affection is 
indicated by sluggish vascular disturbance in the gum overlying the 
offending root. Any fistula existing in the maxillary region, either 
within or without the mouth, should be suspected to have originated 
in a septic pericementitis of some tooth. A soft silver probe should be 
passed along the tract to determine its direction, and, if possible, which 
tooth is aiFected. As a rule, such a tooth exhibits objective evidences 
of abscess, and the patient will give a history of subjective symptoms 
— those of inflammation of pericementum. If the tooth indicated 



414 SEPTIC APICAL PERICEMENTITIS. 

as the affected one be free from caries, the thermal test should be 
applied to determine the degree of vitality of the pulp. Should the 
tooth not respond to applications of cold, it is possible it may offer 
slight response to applications of heat. It is next examined by 
light reflected from the ordinary, or, better, the electric mouth- 
mirror, when, if the pulp be dead, opacity of the crown will be 
detected. An abscess upon an upper incisor opening upon the nasal 
floor may cause a discharge simulating that of ozaena. An examination 
of the nose will reveal a teat-like elevation upon the mucous membrane 
covering the nasal floor and an incisor beneath w T ill be found carious 
and having a putrescent pulp, or, if non-carious, there will be a history 
of traumatic pericementitis and upon inspection an opacity. It may be 
mentioned here, in connection with death of the pulp from trauma- 
tism, that continuous thread-biting, and biting very hard substances, 
such as pieces of ice, nuts, etc., may cause death of the organ, pre- 
sumably by thrombosis. 

It is possible that the direction taken by a probe passed into the 
fistula will point away from the teeth present, passing into a space from 
which a tooth has been extracted. In that event the presence of a root- 
fragment, or piece of necrosed process, may be suspected. 1 If the 
neighboring teeth be excluded as causes of the inflammation, there 
should be no hesitation in making an exploratory incision down to the 
end of the probe which has been passed into the fistula ; cases of den- 
tigerous cysts have been detected in this manner. This condition, how- 
ever, should be suspected when there is an absence of a tooth or teeth 
from the arch, no evidence, past or present, of pericementitis in any of 
the teeth of the arch, and a cystic tumor present in the jaw, or a fistula 
discharging upon the face after a history of maxillary periostitis. 
Caries or necrosis, although in many cases the result of septic apical 
pericementitis, may exhibit fistula opening into the mouth, Avithout 
evident connection with the teeth. As a rule, cases of necrosis exhibit 
marked evidences of chronic inflammation of the tissues overlying the 
dead or dying bone ; there are usually several fistulse discharging from 
it, Caries may present but a single fistula and closely simulate ordinary 
alveolar abscess. Diagnosis is made by passing an excavator through 
the fistula. Dead bone is readily detected by touch ; it has a rotten 
feel. In caries the instrument may be passed through the dead bone in 
various directions, and a characteristic sound be elicited by tapping 
upon it. Careful examination of the teeth must be made in all of these 
cases to determine the condition of the pulps and pulp-canals. In pass- 
ing an instrument through a fistula to the apex of a tooth-root, 
where the disease-process has been of long duration, it may be found 
1 See case of Black's, American System of Dentistry, vol. i. 



CHRONIC ALVEOLO-DENTAL ABSCESS WITH FISTULA. 415 

that the apex of the root is denuded of pericementum and roughened ; 
that is, the apical cementum is necrotic ; foreign deposits may be 
detected occupying portions of the necrotic area. 

Treatment. — The first step of treatment is the thorough eradication 
of the source of infection. The tooth, filled or unfilled, bearing arti- 
ficial crown, or no matter what its condition, should have its root-canals 
freely opened to their apices. The presence of a canal-filling should 
not hinder the complete opening, as the canal may appear to be filled, 
and in reality be imperfectly filled. If the abscess be upon a root 
which cannot be utilized by crowning, the root should be at once 
extracted. Impacted teeth should be removed by surgical operation. 
If the centre of suppuration be dead bone, it should be removed by 
like means. 

In cases where there are useful tooth-roots, the tooth should be 
isolated under rubber-dam, and saturated sodium dioxid solutions be 
pumped into the canals until it is certain they are cleansed and steril- 
ized. Fine canal-cleansers are then passed through the apex of the 
aifected root, opening into the abscess-cavity. The canal and cavity 
are now freely syringed with 3 per cent, pyrozone until the contents of 
the abscess-cavity are driven bubbling through the fistula. This forcible 
irrigation is continued until the fluid comes away clear and without 
bubbling. M. L. Rhein l advises that a solution of mercuric chlorid 
in hydrogen dioxid be used for this washing. The wall of embryonic 
tissue lining the abscess-cavity being frequently infected with organisms 
which the hydrogen dioxid alone fails to kill, mercuric chlorid is added 
to destroy them. The same writer 2 advises that a positive electrode, a 
fine wire of chemically pure zinc, be inserted to the bottom of the canal 
and the current from a cataphoresis apparatus applied. By electrolysis, 
zinc oxychlorid is formed at the positive pole by the action of chlorin 
and oxygen, liberated from the fluids of the part, acting upon the zinc ; 
the zinc oxychlorid in its nascent state is forced cataphorically into 
the walls of the abscess, where it acts as an effective antiseptic and 
induces the formation of granulation-tissue ; hence the regeneration of 
tissue. 

The usual practice is to fill the root-canal with some powerful anti- 
septic, such as campho-phenique, the 1-2-3 mixture of Black, or one 
of the antiseptic oils, and, by pumping with a smooth broach, force the 
antiseptic through the abscess-cavity and fistula. Fluids may be induced 
to flow an astonishing distance if the pumping be persisted in. They 
will make their way along such tracts as shown in Figs. 319, 321, 
and 322. 

Their flow may be induced in some cases by dipping a sterilized 

1 Items of Interest, 1897. 2 Ibid. 



416 



SEPTIC APICAL PERICEMENTITIS. 



Fig. 323. 




rubber cleaning-cap (Fig. 323) in mercuric-chlorid solution and pressing 
it firmly upon the gum over the fistula, then relaxing the pressure until 
the cap rises and draws the antiseptic in the canal, 
along the abscess-tract. 

The canal is dried and filled with the paraffin- 
aristol mixture, or with thread dipped in an anti- 
septic oil, and the crown-cavity hermetically sealed. 
Nature should now complete the cure by obliterating 
the abscess-cavity with embryonic tissue, which sub- 
sequently organizes. In twenty-four hours but a 
slight serous flow should be noted, the patient having 
been directed to use antiseptic mouth-washes freely. 
In about three days no exudation should be present, 
and in a week the fistula should be healed. Unless a 
pus-discharge be observed, the tooth should remain 
sealed for a week, or, better, two weeks, and if filled 
with paraffin may remain permanently sealed. If pus-discharge appear, 
the tooth should be opened and treated as before. 

If the case be one where an artificial fistula has been established, the 
wound should be kept from healing, after the antiseptic washing, by 
packing it daily with nosophen-gauze. 

If a serous discharge persist longer than a week, a root-apex 
denuded of pericementum, saturated with noxious material, and prob- 
ably encrusted with deposits of calculi, may be 
suspected (Fig. 324). A sterilized excavator 
should then be passed into the fistula and over 
the apex of the root, to discover the amount of 
denudation and the presence of deposits. If 
deposits be discovered, the root should be solidly 
filled; and nosophen-gauze be forced into the 
abscess-cavity, distending the fistula ; if the latter 
be small, it may be enlarged by an incision and 
then packed. As soon as free exposure of the 
root is obtained a fissure-bur may be used to cut 
off the portion of root projecting into the abscess- 
cavity ; the cut edges of the root may be rounded by means of scalers. 
It is a serviceable measure to scrape the abscess-walls in these cases, 
removing the debilitated and degenerating tissue and inducing healthy 
granulation. The cavity is packed with cotton and phenol sodique 
until bleeding ceases, and a packing of nosophen-gauze is inserted, to be 
renewed in daily lessening amount until the abscess-cavity is filled with 
granulations. The patient should use freely antiseptic mouth-washes. 
Each fresh packing should be preceded by an antiseptic douche. 



Fig. 324. 




Chronic abscess, showing 
denudation of apex of 
root (a to b), with de- 
posits of calculi (a) upon 
cementum. 



CHRONIC ALVEOLO-DENTAL ABSCESS WITH FISTULA. 



417 



In some cases of anomalous root-form, such as a sharp bend upon 
the upper end of the root, which renders it impossible to gain access to 
the apex of the root even with the aid of sulfuric acid, it may be neces- 
sary to treat the abscess through the fistulous opening. The roots 
should be sterilized and cleansed to as great a depth as possible with 
the aid of sulfuric acid and fine cleansers, and an endeavor made to 
force hydrogen dioxid through the apical foramen and 
out of the fistula by means of a syringe. The cavity 
of the crown should be filled with pink gutta-percha, 
and through it the nozzle of a syringe filled with 3 per 
cent, pyrozone thrust well up the canal. When the 
piston of the syringe is forced down, the solution may 
appear at the opening of the fistula, or it may fail to 
penetrate the foramen, and the backward pressure may 
force the gutta-percha from position. In that event 
myrtol should be placed in the canal, which should be 
filled with thread holding the same material. Three per 
cent, pyrozone should then be injected into the abscess- 
cavity through the fistula until effervescence ceases. 
The nozzle of a minim syringe (Fig. 325), charged with 
campho-phenique, or the 1-2—3 mixture, is then passed 
into the abscess-sac, and a couple of drops deposited. 
In very many cases the abscess will then proceed to 
recovery. The treatment should be repeated, if neces- 
sary. If several dressings applied at intervals of a 
week do not cause a disappearance of pus-formation, 
amputation of the offending portion of the root will be 
necessary. A heroic method of treating chronic ab- 
scesses which obstinately refuse to heal is by extraction 
and replantation. The method applies only to single- 
rooted teeth, although it has been successfully per- 
formed upon molars. The patient's mouth is to be 
sterilized, and the tooth extracted. The tooth is im- f ? | 

mediately placed in a solution of 1 : 1000 mercuric ~~\ 

chlorid at a temperature of 120° F. It has been 
repeatedly asserted, but without satisfactory demon- 
stration, that the cells of the deeper layer of the 
pericementum and the cementoblasts, and also the 
cement-corpuscles, retain their vitality for some period after extrac- 
tion, and immediate replantation results in a re-establishment of 
the physiological union between the teeth and alveolus. It is certain, 
however, that measures which are necessary to thoroughly sterilize 
the tooth before its reinsertion would be fatal to any cellular vitality 

27 




Minim syringe. 



418 SEPTIC APICAL PERICEMENTITIS. 

which might exist in the cementum and its covering. The pulp- 
canal is opened from its apex and cleaned out with canal-cleansers, and 
a 25 per cent, solution of pyrozone placed in the canal, where it is 
allowed to remain for some time. In the meantime the socket from 
which the tooth has been removed is syringed with pyrozone, and should 
the pericementum not adhere to the tooth the depth of the socket is 
scraped by means of large spoon-excavators to remove the tissues impli- 
cated in the abscess. The cavity is washed with pyrozone, and a pledget 
of cotton, which has been dipped in campho-phenique, is placed in the 
socket at its bottom. The tooth is dried by means of warm air; the soft 
tissues at the apex, if any be present, are cut away for about one-eighth 
of an inch. The canal is filled with gutta-percha or filled solidly with 
gold, the end of the root cut oif as far as it has been denuded of peri- 
cementum, smoothed, and returned to the antiseptic solution. The 
cotton is removed from the tooth-socket, which is syringed with 3 per 
cent, pyrozone, and the tooth returned to position. It is tied to the 
adjoining teeth by means of silk ligatures or held in place by an appro- 
priate retaining appliance. 

A chronic abscess may discharge into the maxillary sinus for a 
long period before being discovered, unless the pus-accum illation be 
extensive, Avhen it escapes from the antrum into the cavity of the nose, 
discharging by one side. Smaller accumulations of pus find exit in the 
recumbent position, and attention is called to one antrum as the seat of 
affection by noting that in the morning pus appears at but one nostril. 
The discharges from purulent nasal catarrh appear upon both sides. 

A more common history of antral empyema is the patient's complaint 
of dull, heavy pains and uneasiness over one side of the face, and an 
offensive odor, which may not be evident to the operator. High illum- 
ination of the mouth by means of the electric mouth-mirror may reveal 
the presence of fluid in the antrum. Examination of the posterior teeth 
will show one of them to be pulpless. If such a tooth be extracted, a 
profuse flow of pus may follow, and a probe may be passed through an 
alveolus directly into the antrum. Although this is the usual surgical 
relief, dental conservatism rebels against the immediate condemnation 
of the offending tooth. Efforts at curing the antral condition through the 
pulp-canal are well-nigh hopeless — the antrum is entered at some other 
point. The tooth is treated as any infecting root ; is sterilized and filled. 
The most certain spot of entry to the antrum is about one-quarter 
inch above the buccal roots of the upper first molar. The part, or the 
patient, is anaesthetized, and the soft tissues incised or a section removed 
by means of a tubular knife ; a drill or trephine at least one-eighth inch 
in diameter, driven rapidly, is passed upward, backward, and inward, 
piercing the thin shell of the antrum at this point. The nozzle of an 



CHRONIC ALVEOLO-DENTAL ABSCESS WITH FISTULA. 



419 



atomizer, filled with a 3 per cent, solution of pyrozone, which has been 
rendered alkaline by sodium dioxid and warmed, is passed into the 
antrum and the cavity is freely sprayed. A probe is passed into the 
cavity and an exploration made to detect the presence of any dead bone, 
which, if found, must be removed, the cavity of entrance being enlarged 
to permit its removal. The cavity is sprayed about every other day 
with very dilute, warm Dobell's solution. 

In cases of long-standing chronic abscess, with fistula opening at a 
distance, the fistula may refuse to heal. In that event the tract should 
be scraped and painted with 20 per cent, silver nitrate solution. If 
healing does not occur, the oifending tooth should be extracted. 

In fistulas discharging upon the face the formation of scar-tissue may 
bind the tissue of the cheek tight to the bone. When this occurs 
beneath the tip of the chin, the scar, after healing, usually resembles 
a dimple, and calls for no interference. The scar and binding down 
along the border of the inferior maxilla, or beneath the malar bone 
in the upper maxilla, may produce deformity calling for remedy (Figs. 
326 and 327). Black's operation is to be performed to lessen the 

Fig. 326. 



Fig. 327. 





Sear caused by alveolar abscess discharg- 
ing on the face. (Black.) 



Operation for the remedy of scar on the face 
caused by alveolar abscess. (Black.) 



deformity, for its complete correction is not practicable. A finger 
placed in the mouth draws the cheek away from the alveolar wall, when 
the exact position of the cord of attachment is discovered. A tenotome- 
knife is passed into the tissues, dividing the band of attachment ; a long 
pin is passed through the most depressed portion of the scar, its centre, 
the long ends of the pin resting upon the face ; strips of adhesive plaster 
laid upon the skin under the head and point of the pin will prevent 
the latter sinking into the soft tissues. The pin is retained for several 
days, until the cut in the mouth heals. 



420 



SEPTIC APICAL PERICEMENTITIS. 



Fig. 328. 



mr 



Chronic Septic Apical Pericementitis (Non-purulent). 

Continued inflammation of a low grade, or what may in reality be 
continued atonic hyperemia, may exist in the apical pericementum for 
long periods without pus-formation. 

Cause. — The cause of the condition is the 
presence of decomposing matter about the apex 
of the root. This is most frequently associated 
with imperfect root-fillings. After apparent ster- 
ilization of canals, their filling has not been com- 
plete, so that serum percolates into the canal and 
in all probability mixes with decomposing tubuli- 
contents. As noted on p. 389, it requires a longer 
time and more complete and stronger antisepsis 
to completely sterilize canals than are usually 
given. Miller's 1 experiments have shown that 
the infection of root-tubuli is only for a scant 
depth (Figs. 328 and 329), and that minute frag- 
ments of the pulp itself must be regarded as the 
offending agents. It is only by way of the pulp- 
canal that infection need be feared. The depth 

Fig. 329. 



1> 




Fig. 328.— Sector of a cross-section from a diseased root : a, cement ; b, stratum granulosum ; 
c, very narrow and finely branched tubules. X 150. 

Fig. 329.— Dentin from the root of an abscessed tooth, showing the penetration of cocci to a 
depth of about T x s mm. ( 2 i B in.) ; the side a-b bordered upon the canal. X 1000. (Miller.) 

of bacterial penetration into the tubuli will show infection laterally 

1 Dental Cosmos, 1890. 



CHRONIC SEPTIC APICAL PERICEMENTITIS. 421 

through tubuli and cementum to be highly improbable. A chronic 
inflammation is usually noted in connection with non-carious teeth 
whose pulps have died in consequence of injury to the apical vessels. 

Symptoms and Diagnosis. — The symptoms of this condition are 
tenderness upon decided pressure or upon percussion ; the response may 
only be elicited by pressure or percussion in one direction. The tooth 
gives a dull note upon percussion and is usually looser than its neigh- 
bors. The red line of the gum extends farther toward the gum-margin 
than normal — quite to it in some cases. Evidences of a dead pulp are 
sought ; large fillings, the presence of opacity in the tooth, or a mark- 
edly different color from that of its neighbors, all point to this ; which 
an examination with the reflected light of an electric mouth-mirror con- 
firms. The tooth by this light is seen to differ in opacity from its 
neighbors. 

An effective method of application of the thermal test, is that sug- 
gested by M. L. Rhein : the tooth is isolated and a spray of methyl 
chlorid is directed against it. A live pulp responds immediately to 
the intense cold produced ; a dead pulp fails to respond. 

Examination of the tooth is made to see whether it occludes im- 
properly ; if a filling be present, whether the latter show occlusion- 
marks ; excessive occlusion gives rise to symptoms resembling those 
of chronic septic apical pericementitis. If faults in this direction 
exist, they are to be corrected and the effect noted. If they do not 
exist, a septic origin is diagnosed. 

Treatment. — The treatment is that of pulp-gangrene : the tooth is 
sterilized and isolated, and its root-canals entered to the apex and 
sterilized. The presence of decomposing organic matter is shown by the 
bubbling which ensues when a 25 per cent, solution of pyrozone is 
placed in the canals. Canal-fillings are removed even when apparently 
perfect. The condition is common under cotton canal-dressings, the 
latter usually emitting an offensive odor. Gutta-percha stoppings are 
warmed by blasts of hot air and removed by fine hooks. Oxvchlorid 
fillings are removed by means of sulfuric acid, which is also applied to 
all fine canals containing no fillings. Gold, tin, and amalgam root- 
fillings are practically irremovable. A careful examination is always to 
be made for extra canals. 

There can be no assurance of safety until a fine canal-cleanser can be 
carried to the apex of the root, until the patient winces. The cleansing is 
to be accomplished with strong sodium-dioxid solutions. In case of failure 
to reach the apex, after a prolonged cleansing with sodium dioxid, the 
canal is washed out with a solution of hydrochloric acid, a zinc electrode 
inserted in the root, and a cataphoric current applied ; the zinc oxy- 
chlorid formed is forced into all interstices. This action should not 



422 SEPTIC APICAL PERICEMENTITIS. 

be prolonged, or the pericementum may become very much irritated by 
an excessive amount of the zinc salt. Such canals are best filled by 
first thoroughly drying, then flowing into them the melted paraffin and 
aristol mixture, and thrusting into the fluid filling a long, slender, 
metallic point, made hot. 

If the pericementitis have been of long standing, the thickening of the 
membrane will have caused protrusion of the tooth. The tooth should be 
ground off at its point of occlusion until it occludes with somewhat less 
force than its neighbors, the therapeutic principle in these cases being 
that of removing the source of irritation and procuring surgical rest. 
Indications of favorable results are found in the red gum-line assuming 
its normal position, tenderness disappearing, and increased tightness of 
the tooth. 

This affection is extremely common about the roots of pulpless teeth, 
and always signifies more or less enforced disuse of the teeth, and, if 
uncorrected^ their ultimate loss. 



CHAPTER XXIII. 



NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

Apical and general pericemental disturbances of a vascular type 
and of non-septic origin present in two classes, the acute and the chronic. 
For purposes of classification they may be grouped as follows : 



Acute 



f Blows. 

Wounds. 
I Wedging. 
I Orthodontia. 

J Non-septic. 
i Septic. 

Canal medicaments. 



Chronic 



Acute also. 



Traumatic pericementitis 



Perforated roots 

Chemical agencies 
f Perforated roots. 
Excess of root-filling 
Excess of crown-filling 
Resorption of roots. 
Hypercementosis (exostosis). 

f Traumatisms. 
Over-use of teeth 
Misuse of teeth 
Disuse of teeth 
Impacted third molars 
Drug-action. 
Gout. 
Scurvy. 
Syphilis. 



Traumatic Pericementitis. 

By traumatic pericementitis is meant an inflammation (profound irri- 
tation) of the pericementum, the result of mechanical violence. Accord- 
ing to the nature and mode of action of the injurious force, the apical 
or any other part, or all parts, of the pericementum may be affected. 

Causes. — The causes of this condition are many and varied ; a 
transient traumatic pericementitis may be excited after arsenical appli- 
cations to kill the pulp, by forcibly removing the pulp while it still 

423 



General Aseptic 
Pericementitis 



} 

} 



Mal-occlusion. 
Non-occlusion. 



424 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

retains a vital connection at the apex ; by forcing the root-filling 
material beyond the apex of the root, particularly if the material be of 
an irritating character, such as zinc oxychlorid. The presence of a 
neutral canal-filling projecting into the pericementum usually causes a 
continued pericementitis of a lower grade. 

The passage of irritating chemical substances used in sterilizing canals 
may light up a transient pericementitis. Pericementitis following the 
introduction of sodium-dioxid or sulfuric-acid solutions usually sub- 
sides quite promptly ; if strong solutions of zinc chlorid or mercuric 
chlorid have caused the inflammation, it may be more pronounced and 
of longer duration. 

The passage of reamers through some lateral aspect of a root may 
light up a pericementitis which resists all treatment. These cases, fre- 
quently, are infected either at the time of injury or at a later period. 

Too violent wedging is always followed by more or less pericemen- 
titis of the wedged teeth and their neighbors, more marked when elastic 
rubber wedges are used. 

In correcting irregularities of the teeth, if they be moved too rapidly, 
are not firmly directed during the operation, or subsequently not firmly 
maintained in position, pericementitis of a high grade is frequently 
excited. 

The excessive use of the mallet in building down fillings, particularly 
upon pulpless teeth, may be followed by pericementitis. 

The biting of hard substances, such as nuts and pieces of ice, and 
notably thread -biting, are prolific sources of traumatic pericementitis. 

In addition to these, falls, blows received upon the teeth, and blows 
received under the chin, bringing the teeth forcibly together, all induce 
pericementitis, which may vary in degree from a passing soreness to 
general osteitis and perhaps necrosis. 

Prophylaxis. — It will be observed that the majority of these causes 
are associated with operative dental manipulations, or dental abuse by 
the patient, and are in a large degree preventable. In treating pulp- 
canals with such agents as a 50 per cent, solution of sodium dioxid, or 
a 50 per cent, solution of sulfuric acid, care is taken as the end of the 
canal is approached not to pump them through the apex, and to neu- 
tralize, with an acid in one case, an alkali in the other, at the end of the 
sitting. Strong solutions of zinc chlorid or mercuric chlorid are kept 
away from the apices of roots. In case zinc oxychlorid is used as 
a canal-filling, the apex of the root is gently sealed with a small pellet 
of cotton containing an antiseptic oil, or, better, a small cone of softened 
gutta-percha. Canal-fillings are inserted gently and withdrawn as soon 
as sensitivity is noted ; by introducing too large a root-filling mass, air 
may be imprisoned between the filling and the apex of the root, exciting 



TRAUMATIC PERICEMENTITIS. 425 

a reaction as though the filling itself had been passed through the apical 
foramen. Teeth are to be supported mechanically while large gold-fill- 
ings are being malleted into them. The support is derived through 
judicious placing of wedges. Severe malleting should not be practised 
except the pericementum be healthy. 

Gradual wedging should supplant the violent wedging with rubber. 
The latter, when used at all, should be in thin layers, and the wedging 
completed with tape or wooden wedges lightly applied. Malleting 
should not be done upon wedged teeth until, after a period of rest, peri- 
cementitis has subsided, and unless the teeth are rigidly held during the 
filling operation. 

Orthodontic appliances should be of such types as permit a gradual, 
steady advance in tooth-movement ; and when the irregularity is cor- 
rected the tooth should be maintained firmly in its new position until 
the surrounding tissues hold it firmly. 

Patients should be warned against the evil effects of thread-biting 
and biting hard substances. 

Symptoms and Diagnosis. — The general symptoms are soreness 
and looseness of the tooth, together with varying degrees of vascular 
disturbance of the gum overlying the tooth. A diagnosis may usually 
be made by obtaining a history of the case, by excluding septic influ- 
ences as probable causes, and by the disappearance of the disorder upon 
applying treatment indicated in traumatic injuries. 

Clinical History. — Cases due to the passage of irritating chemical 
substances through the root-apex subside, as a rule, after a period of a 
few days. Cases due to the presence of a protruding root-filling usually 
become chronic, and secondary pathological processes arise. Cases due 
to wedging subside, as a rule, after a period depending upon the severity 
of the wedging and peculiarities of the individual. Permanent injury 
may be done to pericementum from such causes, and a predisposition 
to degenerative changes be established. The pericementum may be- 
come permanently debilitated and perfect tissue-regeneration or organi- 
zation be prevented in tooth-regulating, if the teeth are permitted undue 
mobility during regulating or not firmly splinted afterward. In cases 
due to direct and sudden violence to the pericementum, blows upon the 
teeth, and the crushing of hard bodies, etc., the acute symptoms may 
disappear after a period governed by the degree of violence and of tis- 
sue-reaction. In these cases, however, and in those of thread-biting, 
strangulation or thrombosis of the pulp-vessels may occur in conse- 
quence of the pericementitis, and at later periods pulp-decomposition may 
occur and give rise to the septic forms of pericementitis. 

Pathology and Morbid Anatomy. — In cases caused by the action 
of irritating chemicals, the latter cause destruction of an amount of 



426 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

tissue, and the vascular system and cells react to remove the dead tissue. 
The amount of tissue-death depends directly upon the amount of the 
chemical present, the vascular reaction being in correspondence. Pre- 
sumably the pericementitis persists in some degree until the foreign 
(dead) material is removed by natural processes. 

An excess of root-filling material introduces a foreign body into a 
sensitive vascular tissue, and presumably the changes noted as due to the 
presence of foreign bodies in other parts occur — an attempt at removal 
by phagocytes and subsequent encystment (see Resorption of Roots and 
Hypercementosis). 

In cases due to traumatism, such as. violent wedging, rapid move- 
ment in regulating, overmalleting, blows, thread-, ice-, and nut-biting, 
etc., the condition is surgically one of bruise. 

The phenomena of active inflammation make their appearance to an 
extent governed by the degree of violence — exudation, swelling, red- 
ness, and pain ; fibrinous and corpuscular exudations occur, and later a 
reorganization of tissue occurs, in some cases a degeneration, depend- 
ing upon the completeness with which the indicated therapeusis is 
applied and upon the vitality of the patient. 

Traumatic pericementitis in high degree in the young may be recov- 
ered from ; but in the middle-aged and aged it may give rise to a series 
of degenerative changes which only end with the loss of the tooth. 

Cases due to perforation of the root and wounding of the pericemen- 
tum, after the acute symptoms have passed, commonly assume an irri- 
tative and chronic type, the soft tissues included in the perforation being 
in a state analogous to an ulcer. Many of these cases become infected 
owing to the difficulty of completely sterilizing the apical portion of the 
canal which lies beyond them. 

Treatment. — If the cause of the condition be still in action, it is 
to be removed or neutralized. In all cases due to violence the treat- 
ment is that adapted to injury ; first, surgical rest of the pericementum. 
This may be accomplished in two ways ; either by preventing the tooth 
striking its antagonists, or holding it so rigidly that it cannot move if it 
does meet them. As a preliminary measure the tooth is gently but 
firmly lashed to its neighbors by means of ligatures so that it is rigidly 
held. A swaged cap is either fitted to a neighboring tooth, or the 
antagonizing teeth are ground away until they fail to strike the injured 
tooth ; the first method is to be preferred. 

In cases involving several teeth, such as all of the incisors, two me- 
tallic plates are quickly swaged to cover the posterior teeth and they 
are cemented in position. 

Cases due to mild injury may disappear after painting the overlying 
gum and surrounding territory with tincture of iodin. 



CHRONIC APICAL PERICEMENTITIS. 427 

A inouth-wash which affords marked relief in many cases is extract 
of hamamelis, used in one-half strength several times a day. 

Acute pericementitis due to the passing of a canal-reamer into some 
lateral aspect of the pericementum may occur once in the history of a 
practitioner ; it never should twice. Reaming should be done with 
such care and deliberation that the operator is certain of the direction 
taken by the reamer, and he should be prepared to cease reaming as 
soon as canal curvature is felt. Before a reamer removes the last 
portion of cementum, separating the instrument from the pericementum, 
sensitivity is announced by the patient, and the reaming should cease at 
once. Before reaming any canal, its length and direction should be 
recorded by measuring upon a soft, fine broach. Should sensation and 
bleeding occur before this end is attained, the root has been perforated. 
Sterilization of the canals has presumably preceded the reaming opera- 
tion ; if not, the difficulty is increased owing to the impracticability of 
thoroughly sterilizing the portion of the canal beyond the perforation. 
The canal is syringed freely with a styptic antiseptic ; for this purpose 
nothing is better than phenol sodique. As soon as bleeding ceases, the 
canal is to be filled with some unirritating material which can be placed 
without exercising pressure ; chloro-percha or the paraffin mixture meets 
the indication. Either filling is flowed into the canal until it is full, 
and a central core, a cone of gutta-percha, is gently inserted in the 
fluid filling. 

If evidences of persistent pericementitis are noted about the root 
after this operation, it may be inferred that either the portion of canal 
beyond the perforation is unsterilized or unfilled, or that the perice- 
mentum protests against the presence of the root-filling. Guilford l has 
advised and practised successfully in these cases amputation of the por- 
tion of the root beyond the perforation. 

Chronic Apical Pericementitis (Non-septic). 

Definition. — A non-infective condition produced by the action of a 
constant irritant about the apex of a tooth-root. 

Causes. — Many of the causes of acute inflammation, if of less 
intensity and continuous, or frequently repeated, give rise to the chronic 
condition. Prominent among these is the thread-biting habit. Another 
frequent cause is an overfull filling ; a filling projects in such manner 
that it receives an excessive impact during mastication. A projecting 
root-filling of any substance, causes continued irritation of the peri- 
cementum into which it projects. An analogous condition may exist in 
perforated roots which have been filled. 

Symptoms. — The symptoms of the condition are redness of the 
1 Proc. Academy of Stomatology, 1897. 



428 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

overlying gum, tenderness upon percussion, and some degree of loose- 
ness of the tooth. 

Effects. — The effects of this condition may vary according to the 
extent of the irritation and its duration. The irritation may in point 
of effect be but a continued stimulation of slight or high degree, in 
which event the effects of stimulation follow — i. e., prolonged arterial 
hyperemia and its results. The condition may be one of over-stimula- 
tion or irritation proper, with corresponding results. There is much 
evidence to show that the degree and quality of irritation vary. In- 
flammatory degeneration may occur — i. e., a formation of embryonic 
tissue which fails of complete organization, or degenerates. The debili- 
tated part may become infected. 

Diagnosis and Prognosis. — The diagnosis of the condition itself is 
usually made without difficulty, but its nature and causes may at times 
be very obscure or difficult of detection. It is observed whether some 
part of a filling or of the tooth itself receives undue impact in mastica- 
tion ; if so, the redundant substance is ground away, and the effect 
noted. Look well to the incisors and note whether they occlude cor- 
rectly. A history of the case, when obtainable, is of first importance. 
Knowledge of the nature and thoroughness of the canal-filling, the 
medicaments used, etc., is a valuable guide. The discovery of the 
cause of the condition can only be made by exclusion ; possibly exist- 
ing causes are excluded one by one, in the order of their probability. 

The prognosis of the case will depend upon the completeness with 
which the exciting cause of the condition can be removed, and the char- 
acter of the pathological changes which have occurred. 

Treatment. — The treatment of the condition consists in the removal 
of the cause, and giving surgical rest. When this is done, provided no 
secondary pathological processes have arisen, the pericementum recovers. 
The occurrence of this condition, due to traumatism about unfilled roots, 
is always a danger-signal. The pulp should be carefully examined to 
determine its vitality. Pulps frequently die of thrombosis arising from 
repeated traumatism of the apical pericementum, and the conditions 
then existing, dead material in proximity to tissues in a state of hyper- 
emia, invite complicated infections. 

Hypercementosis. 

Definition. — By hypercementosis is meant a secondary deposit, or 
an increase of volume of the cementum of a tooth beyond the normal 
limit. It may be circumscribed or diffuse. 

Causes. — Its occurrence is frequently associated with continued non- 
septic irritation of the pericementum ; its causes, therefore, may be any 
of those described in connection with chronic non-septic pericementitis. 



HYPERCEMENTOSIS. 



429 



It is found associated with other conditions beside traumatic pericemen- 
titis, which conditions will be discussed later. In other cases no direct 
causes can be ascribed to it ; but possibilities in this direction will be- 
come more evident from a survey of its probable pathology. In general 
terms, its cause may be described as a localized or diffused hyperemia 
of the pericementum. 

Pathology and Morbid Anatomy. — The normal mode of formation 
and the history of cemental development must be recalled to make 
pathological formations intelligible. The cementum is deposited as sub- 
periosteal bone in successive layers, beginning before dentinal root- 
formation is complete. 

For some time after eruption of the teeth the cementum consists of 
but few lamella? of deposit. It differs from bone in that its corpuscles, 



Fig. 330. 







imprisoned cementoblasts, are irregularly distributed. The cementum 
is deposited throughout life, so that the teeth-roots of aged persons are 



Fig. 331, 




Hypertrophy of the cementum on the side of a root of a lower molar near the neck of the tooth of 
a man : a, dentin ; b, cementum ; c, fibres of peridental membrane ; from b to c the cementum is 
normal and the incremental lines fairly regular, but at d one of the lamella? is greatly thickened : 
at e this lamella is seen to be about equal in thickness with the others. The next two lamella? 
are thin over the greatest prominence, but one is much thickened at g, and both at h. These 
latter seem to partially fill the valleys which were occasioned by the first irregular growth. 
From a lengthwise section. (Black.) 

covered with thick layers of cementum. The maximum of deposition is 
noted about the apices of the roots, the deposits gradually merging into 



430 



NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

Fig. 332. 





WiaimiaiiiiSiit 



Hypertrophy from root of a cuspid in a man, in which the irregularity is confined to the first lamella?: 
a, dentin ; b, thickened first lamella ; c, subsequent lamellae, which are seen to be fairly reg- 
ular. (Black.) 

the thin lamella of the neck. The deposits occur in successive layers 
or lamellae. The formative activity of the cementum, therefore, 

Fig. 333. 




Apex of root of an upper bicuspid tooth with irregularly developed cementum : a, a, dentin ; 6. 6, 
pulp-canals. The lamella? of cementum are marked 1, 2, 3, etc. ; d, d, d, absorption-areas that 
have been refilled with cementum. It will be seen that the apices of the roots were originally 
separate, but became fused with the deposit of the second lamella of cementum, and that in 
this the regular growth began and was most pronounced. It has continued through the sub- 
sequent lamella?, but in less degree. It will also be noticed that the absorption-areas, d, d, d, 
have proceeded from certain lamella?. That between the roots has broken through the first 
lamella and penetrated the dentin, and has been filled with the deposit of a second lamella. 
Other of the absorptions have proceeded from lamella? which can be readily made out. The 
small points, e, seem to have been filled with the deposit of the last layer of the cementum, 
while others have one, two, or more layers covering them. (Black.) 

normally persists to old age, and, like any other function, is suscepti- 
ble of alterations. It is difficult, therefore, to state exactly where 



HYPERCEMENTOSIS. 431 

pathological hypertrophy begins, and physiological new formation 
ends. Nodular and irregular forms arising from the general surface are 
clearly of abnormal type. They exist as distinct nodular projections 
upon some lateral aspect of the pericementum, as a globular mass at 
the apex of the root, or generally diffused over a greater or less surface 
of the root (Fig. 330). Each of these probably arises from different 
causes. Figs. 331, 332, and 333, exhibit the histological characters 
of the new growth. Outlined portions of the pericementum are seen 
to have exercised their cement-forming function and caused deposits 
of successive lamellse of cementum, in which the cement-corpuscles are 
irregularly distributed as in normal cementum. Areas are seen where 
portions of pre-existing cementum have undergone resorption, and 
where redeposition of cementum has occurred — two distinct vital pro- 
cesses. It is evident that as a result of some irritating influence an 
outlined portion of the pericementum has been the seat of stimulation ; 
its vital activities have been increased, and the energy expended in for- 
mative activity of the cementoblasts. This, it will be observed, is in other 
parts the outcome of continued arterial hyperemia and increased func- 
tional activity, commonly the consequence of an overwork which is 
followed by periods of rest. The inference that some spot of malocclu- 
sion of a tooth, acting as a periodical irritant, is a probable causative 
agent, is clear. Drawing an analogy from other parts, the altered physi- 
ology concerned in hypercementosis is a mild periodical irritation of a 
more or less localized portion of the pericementum. 

It is seen, therefore, how faulty occlusion at some point of a tooth- 
crown may cause overstraining of the pericementum at a point opposite 
to that of faulty impact. Also, how a root-filling, such as a pro- 
jecting cone of gutta-percha, may excite reaction, and at points of 
pericementum distant from the apex, a constant mild irritation (by con- 
tinuity) exist in degree sufficient to produce hypertrophy. Again, in 
other directions, any cause capable of exciting irritation of the peri- 
cementum at or near the neck of a tooth, may cause a vascular reaction 
of milder degree in a more distant part of the pericementum, and thus 
hypertrophy occur. Such causes are found in the irritation induced by 
the edges of projecting fillings, overlapping of cavity-margins by the 
gum, or the presence of deposits of salivary calculi ; all of these are in 
the nature of foreign bodies, and act as mechanical irritants. Hyper- 
cementosis is a possibility in any case of chronic pericemental irritation ; 
it represents a degree of irritation, not any specific isolated causes. 

Symptoms and' Diagnosis. — As the hypertrophy is a result of 
certain conditions, the symptoms when discoverable are those of the 
causative conditions. That hypercementosis has symptoms of its own, 
has never been demonstrated, although a number of symptoms may be 



432 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

associated with the condition and disappear with the extraction of the 
tooth. The symptoms are so vague that none of them can be said to be 
pathognomonic of hypercementosis. The diagnosis of this condition is 
usually made post-mortem ; painful sensations have been experienced, 
the tooth has been extracted, and the hypertrophy seen — the symptoms 
disappeared with the loss of the tooth. It is purely a "post hoc propter 
hoc" diagnosis. The #-ray, however, furnishes a certain means of 
diagnosis. 

Regarding the pathology of the disease, it is evident that the symp- 
toms will be those of a long-continued mild pericementitis. The tooth or 
teeth are very slightly sensitive upon percussion. The gum-color may 
be unaffected ; the tooth may not be loosened. The patient complains 
of a disposition to bite hard upon the particular tooth — to grind upon it, 
if it be a posterior tooth. These symptoms pointing to pericemental 
hyperemia are not necessarily accompanied by hypercementosis, but 
when such teeth are extracted overgrowth of the cementum is frequently 
found. In many cases treatment directed to the relief of the hypersemia 
causes all symptoms to disappear ; that is, if hypercementosis has 
occurred, it has caused no symptoms after its exciting cause has been 
removed. 

Flagg records 1 cases where neuralgias of the trigeminus, painful 
functional disturbances of the eye and ear, etc., have been relieved by 
removing tooth-roots or teeth which were the seat of hypercementosis 
(see Chapter XXVIIL). The diagnosis of pain about the teeth or head, 
due to cemental hypertrophy, can only be made by exclusion. Local 
and general causes of eye and ear diseases having been excluded, the 
teeth should be examined for sources of irritation. When these exist, 
they are usually found associated with pulp-disturbance. If pulp-dis- 
ease can be positively excluded, the possibility of pericemental irritation 
should be taken into account. If any one tooth show a reaction differ- 
ing from its fellows, exhibiting pericemental irritability, particularly if 
upon percussion any increase of the reflex pain be noted, the tooth 
should be extracted, as the possible cause of the neuralgia. If the 
neuralgia disappear, it may be fairly inferred that its origin was dental. 
Entire dentures have been extracted, tooth by tooth, in the vain endeavor 
to cure a neuralgia about the head. The direct diagnosis of hyper- 
cementosis by symptoms is, therefore, very uncertain, and its determi- 
nation as the causative condition of reflex neuralgia still more so. It is 
only by use of the #-ray that the existence or non-existence of hyper- 
cementosis can be positively determined without extraction. 

Treatment. — Any tooth which shows evidence of chronic apical or 
circumscribed pericementitis, even after all discoverable causes of such 

1 Dental Cosmos, 1878. 



RESORPTION OF THE ROOTS OF PERMANENT TEETH. 433 

a condition are removed, is usually condemned sooner or later to the 
forceps. Hypercementosis is a possibility, even a probability, and its 
causes, whatever they be, are still in operation. It is evident, there- 
fore, that the longer the condition persists the greater will be the 
mechanical difficulty in extracting. The extraction, difficult though 
it be, must be complete, or relief from reflex disturbances cannot be 
hoped for. 

(Other phases of hypercementosis will be discussed in connection 
with general aseptic pericementitis.) 

Resorption op the Roots op Permanent Teeth. 

Definition. — By resorption of the roots of permanent teeth is meant 
a condition analogous to that observed upon the roots of temporary teeth 
prior to the eruption of the permanent teeth. 

Patholog-y and Morbid Anatomy. — Both resorption of cementum 
and its redeposition occur in teeth as physiological processes ; at some 
aspect of the cementum the tissue becomes hollowed out, and later 
filled in by new cementum. Resorption of tissue throughout the 
body is accomplished by means of multinucleated cells. At some 
part to be physiologically resorbed these cells make their appearance 
in contact with the tissue to be removed, and it gradually disappears, 
the layer of multinucleated cells constantly occupying the excavated 
territory. 

If a foreign (aseptic) body be introduced into living tissues, it 
becomes surrounded by these cells, which in some cases effect its 
removal ; in others, failing to remove the foreign body, connective 
tissue forms about it and encysts it ; encystment may occur after partial 
removal by giant cells. It has been observed that under conditions of 
irritation about the necks of teeth, such as those produced by the 
presence of foreign bodies, that the hard dental tissues may become 
excavated and deep depressions form. Teeth whose roots have under- 
gone resorption present these conditions : any 
amount of the apical portion of the root has dis- 
appeared (Fig. 334), and if the socket from which 
it has been extracted be examined, it will be found 
filled with a mass of soft tissue, resorption of ce- 
mentum, dentin, and alveolar walls having occurred. 

Teeth which have been implanted, replanted, 
or transplanted, about which union more or less 
perfect has taken place (provided always that suppuration has not 
occurred), if subsequently extracted, are seen to have been the seat of 
tissue-resorption, showing excavations into the cementum and dentin. 
The explanation of these cases is, no doubt, that of the disposal of asep- 

28 




434 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

tic foreign bodies. Teeth inserted into sockets formed from them, re- 
turned to their original alveoli after extraction, or taken from one alveo- 
lus and placed in another, are of the nature of foreign bodies, but least 
of all so, when replanted. If alveolus and tooth be rendered aseptic, the 
insertion of the tooth is followed by the phenomena of mild inflamma- 
tion ; exudation, fibrinous and corpuscular, occurs, and the tissues 
endeavor to rid themselves of an intruding body ; the inflammatory 
reaction soon subsides, and giant multinucleated cells attack the tooth- 
root and endeavor to remove it by solution ; this they accomplish in part 
and in spots ; then a tolerance is established and connective tissue organ- 
izes about the root ; later, more complete regeneration is represented in 
formation of bone. It is understood that in the primary inflammatory 
action some portion of the alveolar wall undergoes transformation into 
embryonic tissue. It will be inferred, therefore, that whenever resorp- 
tion of roots occurs it indicates a degree of irritation in the surround- 
ing vital tissues probably in excess of that producing local hypertrophy. 
As the process occurs most commonly in middle age, it may also be 
regarded as a modified and hastened expression of alveolar atrophy. 

Causes. — The possible causes which may be assigned to this condi- 
tion are naturally those associated with hypercementosis, differing in 
degree. However, another element must enter into the matter to 
determine the peculiar tissue-reaction. For want of a better explana- 
tion these may be called peculiarities of the individual. 

Some of the cases exhibit no tangible cause. Perhaps the most 
common of the causes discoverable is a protruding root-filling. This 
condition has been noted as the probable causative association with the 
peculiar grade and quality of pericemental reaction involved in resorp- 
tion. Cases occur, however, where the tooth is non-carious and the 
pulp is alive, direct evidence of vitality being obtained before and after 
extraction. 

Symptoms. — The tooth may be tender upon percussion, and is 
nearly always loosened ; but unless the resorption have progressed far, 
the latter may not be observed. Later the loosening is peculiar ; the 
tooth moves, as might be expected, with a shortened radius of move- 
ment. The condition may be discovered by accident : evidences of 
mild pericementitis appear, and the pulp-canal is opened to search for 
a cause. The pulp may be found alive ; if alive, and it is killed, or if it 
is found dead, broaches pass suddenly into the mass of soft tissue under- 
lying the root. The progressive loosening of the tooth, with a short- 
ened radius of movement, is about the only constant symptom of the 
condition. 

In cases of live pulp this organ may be hypersemic, so that 
increased response to heat or cold is felt ; this, taken in connection 



GENERAL ASEPTIC PERICEMENTITIS. 435 

with the tenderness upon percussion which can usually be elicited, and, 
with the peculiar loosening of the tooth, is a diagnostic guide. 

Flagg l states that reflex neuralgias occur in this condition, but that 
the most constant indication noted by him was a sense of discomfort 
about the jaws, vaguely associated with some one tooth. The patient 
was convinced that if the tooth were removed, relief would follow. 

In the absence of the peculiar loosening of the tooth, which may 
not occur until the root is nearly gone, a diagnosis is made by exclusion ; 
the resorption is most commonly discovered by entering the pulp-canal 
and finding its length much shortened. 

If the apparatus be available, the a;-ray should exhibit the condition 
with sufficient clearness to furnish an absolute diagnosis. 

Treatment. — Whether the condition be discovered or not, every 
possible source of pericemental irritation should be removed. Usually 
this involves the entrance to and complete cleansing of the pulp- 
chamber ; when the existence of a mechanical irritant in a protruding 
root-filling, a broken broach or reamer projecting beyond the apex, is 
discovered and removed. If pain continue, or neuralgia assignable to 
no other cause persist after removal of all discoverable sources of 
pericemental disturbance, the tooth should be extracted. 

General. Aseptic Pericementitis. 

Definition. — By general aseptic pericementitis is meant a vascular 
disturbance involving all or the greater part of the pericementum, and 
not due to septic causes. Pericementitis is a misnomer in this connec- 
tion, for in some of the cases the essential phenomena of inflammation 
may not be present. The condition may be acute or chronic. 

ACUTE VARIETY. 

Causes. — The causes of acute general pericementitis are mechanical 
violence, the irritation of foreign bodies, notably improperly adapted 
artificial crowns, selective drug-action, and gout. 

Symptoms. — The symptoms of the condition are tenderness or pain 
upon pressure or percussion, loosening of the tooth, with injection of 
the overlying gum ; the swelling, like the other symptoms, is less pro- 
nounced than in septic pericementitis. 

Clinical History. — Cases already described as due to too violent 
wedging, abuses in regulating of teeth, are fitly included under this 
head, as are also many cases due to direct violence, such as blows. 
When artificial crowns of the barrel variety are driven too far under 
the gum, their edges may impinge upon the pericementum and give rise 
to inflammation, which may involve the greater portion of the peri- 

1 Lectures. 



436 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

cementum. Bristles from tooth-brushes, fragments of tooth-picks, and 
other material may be driven forcibly into the pericementum and cause 
inflammation. In all of these cases, beginning at the gum-margin or 
communicating with the mouth-cavity, septic infection almost certainly 
follows. 

If mercury be administered to patients in large doses for long periods, 
or in one or more massive doses, or if the patient have an idiosyncrasy 
to the action of this agent, an irritation of the salivary glands is ex- 
cited, followed by looseness and soreness of the teeth and swelling of 
the gums ; that is, a general pericementitis and maxillary periostitis 
arise. Potassium iodid administered in this condition relieves the 
maxillary periostitis and pericementitis ; but the same drug administered 
in health, or for conditions other than mercurial poisoning, also causes 
irritation of the pericementum. Pilocarpin has a similar effect, though 
in much less degree. All of these drugs are partially eliminated by the 
glandular appendages of the mouth, and during elimination apparently 
act as local irritants. 

Patients who have a gouty heredity, or who are the subjects of 
active gout, frequently exhibit a tenderness of the entire pericementum 
of one or more, or sometimes all of the teeth. This pericemental dis- 
turbance may be the precursor of an acute outbreak of gout in the 
metatarso-phalangeal joint. 

Scurvy — a very rare disease — is attended by rapid degeneration of the 
pericementum of the teeth and of the alveolar tissues. 

Diagnosis and Prognosis. — The history of these cases is all- 
important. Has an injury been received, or is the patient aware of the 
introduction or presence of foreign bodies ? Did the inflammation arise 
immediately after the placing of a barrel crown ? A history of drug- 
administration may be obtained, and the constitutional state produced 
by drug-administration, or by the presence of waste-matters in the circu- 
lating fluids, may be evidenced by a widespread disturbance not having 
a local explanation. 

Cases communicating with the mouth-cavity may become purulent, 
and the condition then becomes acute septic pericementitis, discharging 
at the gum-margin, and the origin of the condition be thus obscured. 
Many of these disorders occur about teeth containing normal pulps, as 
may be shown by the thermal test. 

If the exciting cause of the condition be removable, and degenera- 
tive changes be not too pronounced, complete recovery may be hoped for. 
If the source of irritation continue, degeneration of the pericementum 
usually persists until the tooth is lost, hastened by the infection, which 
nearly always follows. 

Treatment. — The treatment consists in, first, removing the cause, 



VER USE OF TEETH. 437 

which the history of the case usually discloses ; secondly, procure rest 
and reduce the morbid vascular condition. The treatment of trau- 
matic cases has already been discussed. If foreign bodies are present, 
they should be sought for and removed. If the inflammation have 
arisen immediately after adjusting a barrel crown, and has persisted, a 
careful examination should be made for loose particles or project- 
ing masses of hardened cement ; if not found, the crown should be 
removed, the inflammation reduced, and a properly made crown adjusted. 
Cases due to constitutional causes persist as long as the general irritant 
is present ; if this be a drug, as mercury, its elimination is hastened by 
means of potassium iodid administered internally, and the local symp- 
toms reduced by means of strong solutions of potassium chlorate. If 
any of the products of faulty metabolism — uric acid and allied sub- 
stances — be the offenders, they should be gotten rid of by flushing the 
kidneys, using uric-acid solvents : lithium salts, piperazin, etc. In any 
event, the pericementum is to be given a rest through means already 
described, and mouth-washes of hamamelis, etc., advised. 

CHRONIC VARIETY. 

Causes. — Cases of chronic general aseptic pericementitis are usually 
due to either the continuance of some of the causes which gave rise to 
the acute variety, or to overuse, misuse, or disuse of the teeth ; these 
are termed mal-occlusion and non-occlusion of the teeth — either general 
overwork, improper work, or an absence of work. 

The results of overuse, disuse, and misuse of teeth are more cor- 
rectly described as degenerations rather than expressions of inflamma- 
tion, although inflammation, simple or infective, may occur at any time 
in the histories of the cases. The functional abuses comprised in this 
subheading, by inducing degenerative changes, furnish areas of lessened 
resistance, points of determination for the lighting up of the condition 
imperfectly described as pyorrhoea alveolaris. In still other cases local- 
ized areas of cellular debility or even cell-necrosis are found, which 
become infected by pyogenic organisms, forming defined abscess upon 
some lateral aspect of a tooth, the pulp of the tooth being alive, and 
the gingival portion of the pericementum still firmly attached. 

Overuse of Teeth. 

By overuse of a tooth is meant such a variety of occlusion that the 
tooth receives a greater stress than its neighbors, or than it is designed 
to bear. The stress may be received in the normal direction, but be 
excessive in amount. The most prominent cause of this condition is 
the loss of one or more other teeth, permitting undue stress to fall upon 
the neighboring teeth, or, in some cases, on far distant teeth. Too- 



438 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

prominent artificial crowns, particularly those of the all-gold type, 
cause a general increase of stress upon the pericementum. Enormous 
contour-fillings overfull may establish a similar condition. When but 
few isolated teeth remain in one denture and have antagonists, the teeth 
are certain to be overworked. Isolated and other teeth, to which are 
attached clasps of artificial dentures, are in the majority of cases being 
constantly overstrained. 

Pathology. — Like any other functional part which is overworked, 
the pericementum is first stimulated, causing the vessels to dilate. 
Soon evidences of overwork appear in a passive dilatation of the peri- 
cemental vessels, and atonic hyperemia is established. The condition 
passes into one of irritation ; the tooth projects, and is loosened ; the 
overlying gum deepens in color ; and evidences of venous engorgement 
are common. The result of the condition is a softening and degenera- 
tion of the substance of the pericementum ; the alveolar wall is involved 
in the degeneration, and it melts down — disappears to a greater or less 
extent. At any stage of the disturbance infection may occur, and the 
degeneration and destruction of the pericementum be hastened by sup- 
puration, or other secondary degenerations. 

The symptoms, diagnosis, and clinical history are involved in the 
description. The prognosis is the inevitable loss of the tooth if the 
causes be not removed, in which event, the prognosis is governed by 
the extent to which the degeneration has proceeded. 

Treatment. — The treatment is the removal of the causes and pro- 
curing surgical rest until the injured pericementum has recovered. The 
insertion of carefully made artificial dentures is indicated in those cases 
of scattered natural teeth having spaces between them. The prosthetic 
appliance must not be attached to these teeth, nor in its movements 
should it bear against them. No attempt is made, however, to cause 
the artificial teeth strike before the natural teeth in the hope of giving 
surgical rest to these organs. Such attempts always result in failure, 
as they cause injuries to the tissues upon which the plate and teeth 
rest, which are more severe than the pericemental disturbance. 

Properly adjusted bridge-work frequently does good service in these 
cases, provided the over-occluding tooth or teeth be first dressed down 
short of occlusion and are given a period of rest, until the peri- 
cementum recovers. The bridge, if carefully planned, may be made to 
direct and control the stress received by the injured teeth. 

Improperly occluding artificial crowns should have this fault cor- 
rected, by removing the excess of material or by setting properly made 
crowns. 

Overfull fillings should be reduced to correct proportions and shape. 

Teeth which are being strained by clasps should have the latter 



MAL-OCCLUSION OF THE TEETH. 439 

removed. If necessary, a new appliance should be made on which 
clasps are either omitted, or are properly designed for other teeth. 
Surgical rest is the only hope of saving the tooth. 

Mal-occlusion of the Teeth. 

Each tooth of a denture is not only designed to receive a definite 
amount of force, but to receive it in a particular direction or directions ; 
any excess of this force, or alteration of its direction, is followed by 
abnormal stimulation of the pericementum (see Chapter VIII.), and 
by its overstraining. The effects following a general increase of stress 
have been considered under the previous heading. By mal-occlusion 
is here meant, the constant reception of stress by the pericementum in 
directions to which it is unaccustomed, or are not in accordance with 
the anatomical design of the tooth. 

Causes. — Original malpositions of the teeth may cause their faulty 
occlusion. The most prolific source of the condition is, however, altered 
occlusion due to those changes of position of the teeth which follow upon 
the loss of adjoining teeth. 

Artificial crowns which do not occlude in correspondence with the 
other teeth are a common cause. Improperly formed fillings are another 
cause. 

The shifting of positions of the teeth, in consequence of pathological 
changes occurring in or about the pericementum, cause the crowns of 
teeth to occlude improperly. 

Pathology. — The conditions established are either those of overuse 
or of disuse. A typical example of this condition is that of a lower 
second molar which has gradually tilted forward in consequence of the 
loss of the first molar ; or a central incisor which has altered its position 
in consequence of secondary formations in or about the pericementum, 
a common precursor of phagedenic pericementitis. Some portion of 
the tooth, an edge, which before did not occlude with an antagonizing 
tooth, is brought into occlusion ; if the occlusion be not unduly forcible, 
no immediate degenerative changes are evident. If the occlusion be 
excessive, the pericementum is not uniformly affected, but the greatest 
stress is brought to bear upon some lateral aspect of the structure. It 
responds in the degree of the overwork, and degenerative changes occur, 
which, if the active causes be not removed, gradually spread to other 
portions of the pericementum, and the phenomena noted in connection 
with overuse occur, but are not so general in distribution. The tooth 
becomes more movable in one or more directions — L c, is loosened ; it 
may develop some degree of tenderness upon percussion, and the gum- 
color toward the affected side deepens, although it may remain normal 
in other parts. As in the previous cases, infection may — indeed, is 



440 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

likely to — occur, and suppurative processes may hasten the pericemental 
destruction. In some cases the pericementum may degenerate and be 
destroyed about one root of a multirooted tooth, and remain about the 
other. 

Diagnosis. — In all malposed teeth a careful examination should be 
made of their mode of occlusion. If the tooth exhibit tenderness and 
looseness, mal-occlusion is almost a certainty ; it only remains to deter- 
mine its direction. 

The spots of faulty occlusion may be determined by placing a strip 
of carbon paper (articulating paper) over the tips of the antagonizing 
teeth and having the patient bite ; the spots of contact should then 
be ground away until the tooth is slightly short of direct occlusion. 
Fresh strips of paper are used, and the jaws moved laterally, as in mas- 
tication, to note other points of contact ; these should also be ground 
away. When several teeth are aifeeted to any extent, whether by a 
primary shifting of position, without evident vascular symptoms, or 
infection have occurred, and pyorrhoea alveolaris is established, it may be 
advisable to make accurate models of both dentures, mount them in a 
Bonwill articulator, and carefully note the points of undue contact. 
If tin models be made, the points of mal-occlusion may be filed 
away until the occlusion is normal. The positions of the filed 
spots on the models furnish infallible guides for grinding the natural 
teeth. 

The study of these conditions of tooth-usage should be made paral- 
lel with a study of the conditions included under the generic title of 
pyorrhoea alveolaris. 

Prognosis — If the condition be not corrected every time occasion 
requires, the degeneration progresses until the tooth is lost. While 
there are, no doubt, several other factors which act as predisposing 
causes of the ultimate atrophy or necrosis of the pericementum — pyor- 
rhoea alveolaris, phagedenic pericementitis, and gouty pericementitis — 
yet faulty, excessive, or non-usage of the pericementum must take first 
rank as local predisposing causes. 

Treatment. — The principle of treatment is the removal of active 
causes, implying correction of the occlusion ; the removal of dead tis- 
sue, including tooth-roots which are entirely denuded of pericementum ; 
and securing a period of surgical rest. The correction of the occlusion 
has been described under the head of diagnosis. Subsequent correc- 
tions are usually required at intervals. 

Artificial crowns need special scrutiny to see that the occlusal sur- 
faces are properly restored. 

When atrophy and death of portions of the pericementum have 
occurred, conditions are established which are described in subsequent 



DISUSE OF TEETH. 441 

chapters, where their clinical histories, treatment, etc., are also dis- 
cussed. 

Disuse of Teeth. 

Definition. — By disuse of teeth is meant a degree of usage less 
than the amount, the forms, and structure of the teeth and contiguous 
parts fit them for. The disuse may be absolute or relative ; teeth may 
not occlude at all, owing to the loss of antagonists or to extremely 
irregular positions. 

PARTIAL DISUSE. 

Causes and Clinical History. — The meaning of relative disuse needs 
exhaustive inquiry. Black's l experiments have shown that the strength 
of the muscles of mastication, and the amount of stress the pericemen- 
tum will bear, differ with the individual (see Chapter VIII.). One 
person taking a morsel of food, such as a fragment of meat, between 
the teeth may crush it flat with one closure of the jaws ; another will 
require continued mastication to reduce it. The amount of exercise 
the teeth (the pericementum) receive in the first individual is much 
greater than with the second. Moreover, the teeth and alveolar process 
of the first are of a type called highly organized. If in either or any 
case, soft food be substituted for that requiring strong mastication, the 
functional activity of the pericementi is lessened because of lack of 
exercise. Naturally the eifects are in the degree of lessened exercise, 
all other factors being equal ; and this amount is relatively least where 
the teeth are of a type designed for hard usage. 

Pathology and Morbid Anatomy. — Lack of exercise is necessarily 
followed by atony ; and if it occur in a part accustomed to vigorous 
exercise, degenerative changes proportioned to the degree of disuse are 
sequelae. Atony, debility, etc., are followed by the less pronounced 
degenerations, and result in atrophy. In all cases, whether relative or 
absolute disuse, the bloodvessels of the pericementum share in the 
atony, and a passive dilatation or hyperemia results ; lacking in varying 
degree the stimulus derived from mastication (exercise), and the adjunc- 
tive circulatory force exerted thereby, the vascular current becomes 
sluggish, and areas of lessened resistance are formed. The vascular 
conditions are the antecedents of degeneration. The clinical importance 
of the condition at the stage described, is that it frequently precedes 
persistent atrophic conditions of the pericementum — i. e., phagedenic 
pericementitis. In gouty patients it establishes a weak joint, which 
may be the point of deposit of gouty poison. The gum-tissues also 
may become debilitated, owing to the absence of their normal stimuli, 
and passive hyperemias result. Other evils follow ; food-debris collects 

1 Dental Cosmos, 1895. 



442 NON-SEPTIC GENERAL AND APICAL PERICEMENTITIS. 

in unusual amounts, and abnormal fermentations occur, producing gingi- 
vitis (which see). 

Diagnosis and Prognosis. — A diagnosis of disuse (relative) is 
usually made out by inquiring as to the food-habit of individuals. It is 
excessively common in civilized communities, particularly among the 
well-to-do, and is of almost constant occurrence in gourmands. 

Treatment. — Patients should have pointed out to them the results 
of insufficient mastication, together with the evils of faulty oral hygiene. 
Every effort should be made, by the use of antiseptic and mildly astrin- 
gent mouth-washes, to forestall the common sequel of these conditions, 
progressive degenerations and loss of the teeth. These and similar 
conditions are particularly to be feared in the degenerative periods of 
early and late middle-age. It is between the ages of thirty and fifty 
years that ill-consequences are most to be feared from acquired debility 
of the pericementum. 

ABSOLUTE DISUSE. 

Definition. — Teeth which perform no work directly in mastication, 
or indirectly by serving as abutments for a bridge-piece, may be said to 
be in a condition of absolute disuse. 

Results. — A tooth or root whose pericementum receives no stimulus 
becomes relatively a foreign body to the organism. It is a useless part, 
and the body attempts to cast it out. Perhaps these phrases are in- 
sufficiently exact ; however, a disused tooth is lost through a series of 
pathological changes. Teeth which perform no work may be retained 
in the mouths of young children and young adults for long periods with- 
out marked changes occurring in their vital connections, but during the 
degenerative period of life they are usually lost with a degree of rapidity 
differing in individuals. 

The pericemental condition of passive hyperemia following upon 
relative disuse of the teeth has been described ; the condition following 
upon absolute disuse differs in that the pericementum receives no exer- 
cise whatever. The clinical history of these cases is that of a progressive 
extrusion of the tooth ; it projects beyond its fellows in increasing degree. 
The borders of the alveolar process recede, but usually to less extent 
than the tooth protrudes or is extruded. The tooth becomes progres- 
sively looser, until in its latest stages a portion, which may be one-half 
of its root-length, is attached to the jaw through the medium of a mass 
of soft tissue alone ; all true alveolar connection has disappeared. After 
extraction or complete extrusion, the root of the tooth is seen to be 
devoid of pericementum except at the apex of the root. The alveolar 
process has undergone limited atrophy, although in some cases its 
outer walls may be thickened. 



DISUSE OF TEETH. 443 

Pathology. — The passive hyperemia has apparently led to swelling 
and degeneration, with subsequent atrophy of the pericementum, and the 
normal atrophic changes which occur in the alveolar process have 
become hastened and quickened. These cases frequently become com- 
plicated by infections, when the tooth-loosening becomes pronounced. 
The pulp- vessels are cut off and the dead pulp-tissue furnishes a soil for 
micro-organisms, whose poisons hasten degeneration of the tissues in 
the abnormal alveolus. Suppuration may occur — i. e., abscess form. 
Through this process the jaws cast out crownless roots ; in these the 
local alveolar atrophy may be complete before there is external evidence 
of it. The danger of infection is always great in these cases. Some 
degree of infection, no doubt, exists in all of them, which serves to 
explain the increased rapidity of the degenerations. 

Prognosis. — If teeth can be directly or indirectly brought into use, 
so that their pericementi receive exercise, the cases may recover, pro- 
vided the atrophic changes are not very pronounced ; in which event 
the atrophy proceeds, although more slowly. Teeth crowned or made 
abutments for bridges, after degenerative changes have become estab- 
lished — i. e., when the normal pericementum has been replaced by 
a thickened mass of partially organized connective tissue — usually be- 
come progressively looser ; the alveolar atrophy proceeds until all 
attachment is lost. Utilized early, the teeth may be saved. The 
results are better if the teeth or roots be utilized before the age of 
thirty than at later ages. 

Treatment. — The treatment, as might be inferred from the foregoing 
statements, consists in bringing the teeth into use, if the degeneration 
have not proceeded too far. Later, extraction is inevitable. The opera- 
tion, when determined upon, should not be delayed, for not only are 
bacterial growths invited about the loosened tooth, but the soft tissues 
are frequently increased in volume, if extraction be delayed until 
complete local atrophy of the alveolar walls has taken place, a soft and 
spongy mass remains, which interferes with the comfortable wearing of 
prosthetic appliances in the future. 



CHAPTER XXIV. 

PERICEMENTAL DISEASES BEGINNING AT THE GUM- 
MARGIN. 

Nearly all the degenerations of the pericementum which begin 
at the gum-margin are sooner or later accompanied by suppura- 
tive processes, which give a generic name to these conditions, viz., 
pyorrhoea alveolaris. Under this head dental writers have included 
several disease-processes which should be clearly differentiated from 
one another. In general terms, these diseases are characterized by an 
inflammation originating about the gum -margin, and followed by a 
progressive degeneration and atrophy of the pericementum and of the 
alveolar walls. In the areas of pericemental atrophy and death, progres- 
sive deposits of calculi take place, and infection of the disease-territory 
by pyogenic organisms is the rule. Their characteristics, therefore, are 
loss of pericementum in any direction, forming pockets in which calculi 
deposit, and from which pus exudes or may be pressed. The primary 
cause of the atrophy, pericemental necrosis, calculi, and infection are 
so clearly associated with a primary affection of the gums about the 
necks of the teeth, that a critical examination of the causes, clinical 
history, and pathology of inflammation of the gum-margin is a neces- 
sary preliminary to the study of the later degenerations. 

Gingivitis. 

Definition. — The term gingivitis, as at present understood, applies 
to an inflammation confined to the margins of the gum about the necks 
of the teeth, in contradistinction to general inflammation of the gums, 
called ulitis. Fault may be found with this distinction as not being 
warranted by etymology or dictionary definitions, so that perhaps " mar- 
ginal gingivitis " would be a more correct term. 

The causes of marginal gingivitis are local and general, which may 
be subdivided into predisposing and exciting. Any conditions, general 
or local, which reduce the vitality of the tissues forming the gum-mar- 
gins will cause a predisposition to local disease, when exciting causes 
may become operative which before were inoperative. It is still an 
open question whether this is the mode of action of what are known 
as the general or constitutional causes of marginal gingivitis. Be this 
as it may — and it is an important question — marginal gingivitis is an 

444 



GINGIVITIS. 445 

associate of several general disease-states and conditions of faulty metab- 
olism. Rhein Y found after repeated examinations of hospital patients that 
" marginal gingivitis was an accompaniment of typhoid fever, tuberculo- 
sis, malarial disorders, acute rheumatism, pleurisy, pericarditis, and syph- 
ilis, among the acute diseases. Of chronic nutritional diseases, it was 
commonly observed in cases of gout, diabetes, chronic rheumatism, 
several forms of nephritis, scurvy, chlorosis, anaemia, leukaemia, and 
pregnancy. Also in disorders of the central nervous system and fol- 
lowing the administration of mercury, lead, and iodin." 

In some of these disorders, notably typhoid fever and other acute 
diseases, diabetes, pregnancy, and disorders of the nervous system, local 
causes are sufficient to account for the gingivitis, and may completely 
mask connection with the constitutional causes. The connection with 
gout and other arthritic diseases, Bright's disease, anaemic disorders, 
and tuberculosis is clear and undoubted. Rhein states that the grin^i- 
vitis produced by any of the causes named has distinctive features 
which may even serve as diagnostic signs of the nature of the general 
malady. To render the problem less complex, and discover more gen- 
eral causes, the nature of the tissue-changes induced by these diseases 
must be examined. Most of them, it will be observed, may be classified 
as diseases of suboxidation ; diseases in which the oxidizing element 
of the body — haemoglobin — is in reduced amount ; where products of 
insufficient oxidation are formed or retained, and where probably faulty 
oxidation is the result of cell-disorders ; oxygen in insufficient amount ; 
cells unable to oxidize and deoxidize ; oxidizable material in undue 
amount or of imperfect character ; and, lastly, a retention of waste-prod- 
ucts of tissue- and perhaps of food-metabolism in the circulating fluids. 
As in all nutritional disturbances, degenerative disorders most affect 
parts peripheral to the circulation — the parts become debilitated. 

The local causes of gingivitis, some of them probably necessary in 
all cases to the occurrence of the disorder, are more tangible. The local 
causes may be divided into predisposing and exciting. 

The local predisposing causes are lack of exercise, the gums not re- 
ceiving the usual friction and buffeting by food-masses during mastica- 
tion, and permitting the food-masses to remain in contact with the gums, 
where the products of their decomposition act as irritants. The local 
exciting causes are both mechanical and chemical, and act vigorously 
in the degree that local and general predisposing causes exist. 

The mechanical causes are the presence of foreign bodies, such as 
deposits of salivary calculi resting upon the gum or beneath the gum- 
margin ; fillings projecting beyond cavity-margins ; gum overhanging 
cavity-margins ; projecting edges of artificial crowns ; tooth-brush 

1 Dental Cosmos, 1894. 



446 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN. 

bristles ; fragments of bone tooth-picks ; improper contact of the edges 
of prosthetic plates or appliances about the necks of the teeth ; injuries 
inflicted by rubber-dam clamps, ligatures, wedges, etc. 

The chemical causes are the presence in the gum-tissue of irritant 
drugs, probably in process of elimination — lead, mercury, iodids ; the 
contact of caustics applied in the treatment of other dental diseases, 
and chemical poisons generated through the action of mouth bacteria. 
The latter cause probably complicates all the others. 

Symptoms. — The symptoms depend upon the cause. Swelling and 
increased redness of the gum-margins are constant features. In gin- 
givitis due to any of the constitutional causes named, the affection is 
general, but the symptoms are more marked in some diseases than others 
and usually are pronounced in proportion to the neglect of oral hygiene. 
In some cases there may be only a raised, rounded, softened ridge of 
gum, of a bright red color ; but in other cases, the swollen gum may 
obscure fully one-half of the tooth-crown, and the softened tissue be 
purplish in color. 

Prognosis. — The prognosis of marginal gingivitis is governed by its 
causes, the length of time they have been in operation, and the age of 
the patient. Gingivitis commencing at the degenerative period of life, 
particularly when conditions exist which lessen the normal resistive 
power of the pericementum, is certain to establish degenerative changes 
in the latter structure. Degenerative and atrophic changes of the peri- 
cementum and alveolar walls are inevitable in long-continued gingivitis. 

If the trouble be purely local — that is, due to local causes alone — it 
usually subsides promptly upon the removal of the cause. The peri- 
cemental and alveolar atrophy which has occurred makes, however, a 
permanent loss, so that when recovery occurs, the gum-line is seen to 
have receded beyond its normal line of attachment to the teeth. 

Treatment. — The treatment of the condition consists in removing 
the source of irritation and restoring the normal circulation in the 
parts. If the source of the disorder be in some underlying constitu- 
tional condition, the symptoms may be ameliorated, although not 
entirely cured, by the correction of the general disorder. 

Cases due to mechanical irritation are commonly confined to one or 
several teeth, rarely to an entire denture, except cases continued in con- 
sequence of deposits of scaly calculi beneath the gum-margin. Foreign 
bodies, such as bristles and fragments of bone, should be removed. 
Projecting fillings or overhanging crown-margins should be made 
flush with the general tooth-surface. Salivary calculi should be re- 
moved. 

Antiseptic mouth- washes should be employed frequently, no matter 
what the cause. If the gum -tissue be soft and spongy, showing signs 



SALIVARY CALCULUS. 447 

of venous hyperemia, antiseptic, astringent mouth-washes should be 
freely used. 

1^. Zinc, chlorid, gr. x ; 

Aq. menth. pip., ,lj. — M. 

used in spray from an atomizer or as a wash several times a day is an 
excellent local application, meeting both indications. Preparations con- 
taining carbolic acid and allied substances do not appear to act happily in 
these cases. Prescriptions containing eucalyptus and benzoic acid are to 
be preferred : 

ly. Acid, benzoic, 3 parts ; 

Tr. eucalypti, 15 " 
Ol. menth. pip., 1 part; 

Alcohol, 100 parts ; 
Saccharin, 2 " — M. (Miller.) 

The above formula diluted one-half is agreeable and efficient. 

Listerine, borine, borolyptol, and other preparations of thymol, boric 
acid, eucalyptus, etc., are all useful when conjoined with the removal 
of every local and general cause discoverable. 

Specific local causes of gingivitis, such as salivary calculi, require 
special consideration. 

Salivary Calculus. 

Salivary calculi are hard formations composed of the calcium salts 
of the saliva w T hich have been deposited or precipitated, and combined 
in an unknown manner with organic substances, usually mucin. 

Occurrence. — They are found upon the surfaces of the teeth, notably 
in situations opposite the mouths of the salivary glands ; in the ducts 
of the muciparous salivary glands (sublingual and submaxillary), and 
beneath the margins of the gums. 

Varieties. — Clinically three varieties of salivary calculi are recog- 
nizable : first, the soft, friable, whitish-yellow deposits found upon the 
buccal surfaces of the upper molars and upon the lingual surfaces of 
the lower anterior teeth ; second, dark-colored and hard deposits found 
more frequently in the latter situation, less frequently in the former ; 
third, dark, hard, scaly deposits found first immediately beneath the 
gum-margin and extending from that point. Deposits upon the teeth 
have been divided into salivary and sanguinary or serumal, ptyalogenic 
and hematogenic calculi (Peirce), and the scaly deposits named have by 
some writers been classified as hematogenic or serumal, which is incor- 
rect ; as stated by Peirce, their origin is ptyalogenic, not hematogenic. 



448 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN 

Serumal calculi are of two varieties, and of different origin from the 
ptyalogenic calculi. 

Causes. — The causes of deposits of salivary calculi are local and, in 
some cases at least, general. The causes will be more evident after a 
study of the conditions under which the saliva deposits its calcium salts. 

The secretion of the parotid gland is more watery than that of the 
sublingual and submaxillary glands ; it contains a globulin but no mucin, 
and contains calcium carbonate, calcium phosphate being present in but 
minute amount. 1 It contains sufficient carbon dioxid to hold the cal- 
cium salts in solution. The secretions of the submaxillary and sub- 
lingual glands contain calcium carbonate and calcium phosphate in 
nearly equal amounts and are rich in mucin ; that of the sublingual 
gland contains the highest percentage of solids, particularly of mucin. 
The mucous glands of the mouth have a viscid secretion (mucin) and 
contain some 20 parts per thousand of solids, organic and inorganic 
(Jacobowitsch). It is, therefore, thicker than the salivary secretion 
proper. The combined secretion, as found in the mouth in conditions 
of health, is a transparent, slimy fluid of alkaline reaction, containing 
epithelial (salivary) cells, and from which carbonic anhydrid may be 
pumped ; sufficient carbonic anhydrid is present to hold the calcium 
salts in solution. As soon as the fluid is exposed, at rest, in a vessel, 
the carbonic anhydrid escapes, and the calcium salts, being no longer 
held in solution, are precipitated, the saliva becoming cloudy. 

In perhaps a majority of human mouths, certainly in the great 
majority of those tested by dental observers, the saliva has an acid 
reaction. Fermentation, particularly lactic fermentation, is so com- 
mon in the human mouth as to be almost a characteristic. It is due, 
no doubt, to the addition of the product of this fermentation, lactic 
acid, to the general saliva that the fluid acquires an acid reaction. 
Similar conditions are established in the mouths of animals fed upon 
cooked starchy foods ; carnivorous and herbivorous animals are affected, 
both domestic, and wild animals in captivity. It has been observed that 
mineral acids, and among the organic acids acetic acid, have the power 
of precipitating the mucin. Lactic acid has a similar property, 2 exhib- 
iting particular features. If to a test-tube half-filled with saliva, a few 
drops or more of a 1 per cent, solution of lactic acid be added, a cloudi- 
ness will appear in the solution ; shred-like coagula of mucin are formed 
which slowly agglomerate and rise to the surface of the solution. If 
the amount of acid be increased, the coagula form more promptly 
and agglomerate quickly in a distinct mass at or just beneath the sur- 
face of the solution. If the coagulum be removed and dried, it is 

1 Halliburton, Chemical Physiology and Pathology, after Mitscherlich. 

2 Burchard, Dental Cosmos, 1895. 



SALIVARY CALCULUS. 



449 



Fig. 335. 



found upon analysis to contain calcium salts. The conditions of the for- 
mation have been, therefore, a volume of saliva in quiescence becoming 
acidulated ; throughout the solution mucin is being coagulated, and at 
the same time calcium salts are being thrown down in consequence of 
the escape of their solvent, carbon dioxid. These salts are entangled 
in the mucin-coagulum as it agglomerates and rises to the surface. The 
dried coagula slowly change color, acquiring a greenish-brown hue. 
Kirk l believes that the connection between the calcium salts and the 
organic substance to be more intimate than a mere cementing together 
of the calcium particles. Conditions exist somewhat analogous to 
those under which calco-globulin forms, and he advances the suggestion 
that salivary calculi may have a family resemblance to calco-globulin. 
To bring about these conditions it is not necessary that mucin should 
undergo coagulation, its inspissation is alone sufficient ; but some ex- 
planation is required of the reasons 
why calculi are found in selective 
situations. 

The human mouth may be divided 
into two cavities, a buccal and a 
lingual ; so far as the accumulation 
of saliva is concerned, the recep- 
tacles form but parts of each of 
these two cavities. A lingual cavity, 
bounded laterally by the lower alve- 
olar walls, beneath by the floor of 
the mouth, above and behind by the 
tongue, is that into which the sub- 
maxillary, sublingual, and numer- 
ous mucous glands discharge their 
secretions (Fig. 336). A cavity 
bounded internally by the buccal 
alveolar wall and buccal surfaces 
of the upper molars, externally by 
the cheek, above by the junction 
of cheek and gum, below bv the 

-, P • A, maxillary sinus ; B, duct of Steno ; C, 

edges of the teeth and cheek, is parotid calculus ; E, submaxillary gland. 

that into which the secretion of 

the parotid gland is poured (Fig. 335). When the muscular appendages 

of the mouth, tongue, cheeks, and lips, are at rest these cavities become 

filled with saliva. The almost constant muscular movements of the 

structures named keep the fluids in a constant state of agitation ; the 

agitation, flow and interchange of fluids are much increased by active 

1 Dental Cosmos, 1895. 
29 




450 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN. 

mastication. Establish now a condition of quiescence, increase the secre- 
tion of mucus by irritating mucous glands, increase also fermentations, 
and new relations are established. The close sympathetic association of 
the branches of the trigeminus must be borne in mind ; irritation of the 

Fig. 336. 

sic 




C, calculus ; S.L. C, sublingual cavity: S. L. G. L., sublingual gland. 

mucous surfaces of the mouth is followed by increased glandular 
activity. Irritation of exposed dentin, or of an acutely diseased pulp, 
is followed by increased glandular activity, and if the irritation be 
prolonged, the character of the secretion is altered. 

The increase, or establishment, of these conditions is found in 
non-mastication ; if one or more teeth, especially upper molars, be in 

Fig. 337. 




Right side, abrasion from over-use ; left side, deposits due to stagnation. 

continuous disuse, it is usual to find accumulations of calculi upon them 
(Fig. 337). If catarrhal conditions of the mouth (increased mucous 



SALIVARY CALCULUS. 451 

secretions) occur and persist for long periods, calculi are almost certain 
to form. As these cases are commonly associated with active oral fer- 
mentations, an increased production of acid occurs. 

The general composition of calculi is usually given l as " calcium 
phosphate and carbonate admixed with mucus and leptothrix." The 
secretion of the parotid gland, containing but a trace of calcium phos- 
phate with its calcium carbonate, gives rise to calculi having a corre- 
sponding composition ; in the calculi upon the buccal faces of upper 
molars calcium carbonate predominates. 

Formation. — Each of the three varieties of salivary calculi exhibits 
different conditions of formation. It is common, however, to find two 
varieties combined — i. e., the conditions of formation have been added 
to one another. 

The typical parotid calculus is soft, friable, and whitish-yellow, 
acquiring density with age. The conditions under which this variety 
forms appear to be more or less disuse of the teeth of that side. This 
is well illustrated in Fig. 337. Owing to the loss of the antagonizing 
teeth of one side, the upper posterior teeth of the same side have fallen 
into disuse : on the opposite side the teeth have all been worn down 
by mechanical abrasion. The disused teeth are heavily encrusted with 
the yellowish friable variety of calculi. The deposit itself probably 
occurs as follows : more or less disorder of the gum-structures follows 
upon lack of mastication — i. e., the mucous discharge is increased ; in the 
buccal cavity (Fig. 335) an accumulation of parotid saliva in a state of 
comparative quiescence takes place ; the gaseous carbon dioxid escapes 
and the calcium carbonate is precipitated ; combining with any adhesive 
matter which may be present, notably the diluted mucous secretion 
of the local glands, collections are formed which lodge in the interprox- 
imal spaces and in the small groove between the gum and tooth. Suc- 
cessive portions of a like character are formed and are added to the 
original deposit. 

The second variety of calculus, that which deposits first upon the 
linguo-cervical portions of the lower anterior teeth, and subsequently 
between the teeth and at the cervico-labial portions, contains a greater 
amount of calcium phosphate and mucin. The light mucous coagula 
found in the lingual cavity rise to the surface of the saliva contained 
in this cavity, and come to rest at the cervico-lingual borders of the lower 
incisors ; the pressure of the tongue, as may readily be tested, tends 
to drive the coagula or inspissated mucus, which entangle the pre- 
cipitated calcium salts, between the teeth, moulding them closely about 
their necks. Subsequent depositions and precipitations occur, which 
cause accretions to the first deposits. When catarrhal gingivitis is 
1 Vergue, Du tartare dentaire et de ses concretions, These, Paris, 1869. 



452 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN 



Fig. 338. 





A, nidus ; B, calculus. 



lighted up from any cause, and it is an inevitable result of the presence 
of these foreign deposits in contact with the gum, it is seen that the 
calculi change their physical characteristics. 

The calculi deposited in the regions of the gingivitis are harder, less 
in amount, and usually dark green in color. They usually intrude 
beyond the gum-margin. The swelling incident to the gingivitis causes 
the formation of a V-shaped depression between the swollen gum-edge 
and the surface of the tooth. It is in these pockets that the hard, green, 
closely adherent deposits occur. Similar deposits may be noted beneath 
the yellow and softer calculi, and if sections of extensive calculi be 
made, these greenish deposits may be seen scattered through the mass. 
The greenish deposits, when they occur alone, are usually in the form 

of very hard scales, closely adherent 
to the necks of the teeth and lying 
within the free gum-margin. 

Sections of extensive calculi show 
them to be made up of concentric 
layers (Fig. 338). Foreign bodies 
are sometimes entangled in the mass. 
In some cases extensive salivary de- 
posits are found associated with highly 
offensive odors ; either their presence, 
or the conditions under which they are formed, appear to invite putre- 
factive decomposition in the mouth. In the mouths of smokers deposits 
of carbon are formed upon calculi, giving them a jet-black surface. 

Pathological Effects of Calculi. — The effects of deposits of salivary 
calculi are immediate and secondary, and their nature is governed largely 
by the character of the deposits and by the existence or non-existence 
of predispositions to pericemental degenerations. In some forms they 
establish immediate predispositions to these degenerations. Their purely 
local significance and effects must first be considered. 

In contact with the mucous membrane, a salivary calculus acts as a 
local mechanical irritant and excites the reaction noted in connection 
with other local irritants ; the form, consistency, composition, and 
smoothness, however, represent a milder type of irritant, and naturally 
their presence is not causative of pronounced inflammatory reaction. 

Figs. 339, 340, 341, and 342, represent the relations of deposits of 
the larger, yellow deposits of calculus upon the lower anterior teeth and 
upper molars. It is seen that these deposits rest on the gum, and do not 
insinuate themselves between gum and tooth in such a manner as to sever 
their attachment. They excite hyperemia of the gum underlying them, 
and resorption of the alveolar walls occurs, beginning at the margin ; 
the pericementum and alveolar periosteum recede w T ith the shrinking 



SALIVARY CALCULUS. 



453 



alveolar wall, gradually lessening the attachment of the tooth. Succes- 
sive deposits of calculi occur, which encroach upon the denuded tooth- 



Ftg. 339. 




Fig. 340. 




Section of a lower incisor, with a large deposit 
of salivary calculus impinging upon and 
causing inflammation of the gum. (Black.) 



Section of an upper molar, with deposit of cal- 
culus on its buccal surface, causing inflam- 
mation and absorption of the gum and 
lower border of the predental membrane 
and alveolar wall. (Black.) 



root. The process is a gradually progressive one, but the rapidity of 
deposit and of alveolar recession varies widely. From beginning deposit 



Fig. 341. 



Fig. 342. 





Sectional illustration of a heavy deposit of 
salivary calculus on a lower incisor, with 
partial destruction of the alveolus of the 
tooth. (Black.) 



Sectional illustration of lower incisor with de- 
posit of salivary calculus less heavy than 
that shown in Fig. 339, but with greater 
destruction of the alveolus. (Black.) 



to almost complete loss of alveolar walls may occupy but a year or two ; 
in other cases the atrophy of the alveolar walls is very slow. Infection 
of the pericementum may occur, when the loss of the tooth is much 
hastened. 



454 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN. 

The teeth become progressively looser until all bony connection 
is lost, being retained at the apex of the root by but few fibrous 
shreds. As soon as the alveolar loss is sufficient to cause marked 
loosening of the tooth, infection of the pericementum is common, and 
suppuration is grafted upon the results of mechanical irritation. 

Prognosis. — The prognosis of this condition depends upon the extent 
of alveolar atrophy. If the loss of support be not so extensive as to 
cause marked loosening of the tooth or teeth, the teeth may be retained 
for an indefinite period, if they be so attached to neighboring teeth as to 
render them firm. If left unsupported, the pericementum is certain to 
degenerate, owing to the increased mobility. The alveolar atrophy will 
continue, and probably infection of the degenerated pericementum occur. 
Redeposit is almost certain unless all morbid conditions are removed 
and extraordinary precautions be taken as regards cleanliness. 

Treatment. — The treatment may be divided under three heads : 
removal of deposits, correction of the effects of their presence, and pre- 
vention of their recurrence. The sole means of removing calculi should 
be instrumental. It is frequently recommended that mineral or some 
of the organic acids be used to soften the deposits to facilitate their 




p 



Scalers. 



removal. Anyone, having seen a case in which a solution (5 per cent.) 
of sulfuric acid had been used for this purpose, needs no further warn- 
ing against the application. Acid solutions will certainly soften the 
deposits, but at the same time inevitably cause a roughening of the 
enamel of the teeth by a solution of the calcium salts. To be sure, the 

Fig. 344. 







acid does affect the calculus more than it affects the enamel, but the 
roughened surfaces of the latter not only invite widespread deposits of 



SALIVARY CALCULUS. 



455 



fermentable material, but render certain the more extensive accumula- 
tions of calculi in the future. The gross deposits may be removed by 
means of large sickle-shaped scales and curved chisels, nearly all used 
with a draw cut (Fig. 343). The instruments should have sharp edges and 
be introduced beneath the deposits, so that the gum is not unnecessarily 
wounded. The scaling should be continued until every surface which 
can be cleansed by these instruments is perfectly smooth. The case may 
then be dismissed for two days or longer ; in the mean time an astringent 



Fig. 345. 



Fig. 346. 



Fig. 347. 






Fig. 348. 




Fig. 349. 




Fig. 350. 



Fig. 351. 





mouth-wash is to be freely used. 
The zinc-chlorid prescription (given 
on p. 447) answers admirably, or a 
mixture of equal parts of listerine 
and extract of hamamelis, diluted one-half with water, is serviceable. 
The passive congestion of the gums will be reduced and swelling lessened 
by these washes, permitting a better view of the surfaces of the teeth. 
More slender instruments of chisel -form which will pass into the spaces 
between the teeth and beneath the gum-margin, without wounding, 
are now required (Fig. 352). All of the calculi visible, and all that 
can be detected by their roughness, are thoroughly detached and 
scraped away by these instruments. The surfaces of the teeth are next 
cleansed with pumice made into a paste with glycerin. The paste 
is applied to the surfaces of the teeth, and the rubber cups and 
small brushes are used to cleanse the labial, buccal, and such lingual 
faces of the teeth as the brushes will reach (Figs. 345 to 351). The 
lingual surfaces of upper and lower incisors are cleansed with moose- 
hide wheels (Fig. 344) and wheel-brushes. The approximal surfaces of 



456 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN. 



I 



Fig. 352. 



the teeth are cleansed with linen tapes armed with the pumice- 
paste. The gums and teeth, as a final measure, are sprayed with 3 
per cent, pyrozone to remove the pumice. It is advisable to repeat 

the polishing with precipitated chalk 
and the same carriers. The astrin- 
gent mouth-wash is advised for a 
week's use ; at the end of this time 
all evidences of gingivitis should 
have disappeared, unless small cal- 
culi still remain under some portion 
of the gum-margin, when their pres- 
ence is denoted by the redness of 
the overlying gum. 

The smoother the surfaces of the 
teeth are made the longer will the 
redeposition of calculi be delayed. 
The operation described, so far as 
beneficial effects are concerned, is 
one of the most important in the 
practice of dentistry. No case should 
be dismissed before it is done ; and 
no long series of operations should 
be begun before the cleansing. The 
patient should, in all cases, upon 
dismissal, be given explicit direc- 
tions as to mastication and its im- 
portance, the wise regulation of 
the dietary, and the advisability 
and importance of using antiseptic 
mouth-washes. 




George H. Cushing's scalers. The 
forms and general character of 
these scalers are well shown. All 
the instruments except No. 6 are 
intended to be used with the push 
stroke. Nos. 1 and 2 are specially 
intended for application to the 
posterior surfaces of lower in- 
cisors : they are also admirably 
adapted for removing calculous 
deposits below the gum between 
molars and bicuspids, and from 
the posterior surfaces of the last 
molars. No. 2 can be passed quite 
to the extremity of most roots with 
less disturbance to the soft tissues 
than a thicker or more rigid in- 
strument would cause. Nos. 3 and 
4 are for removing deposits at and 
below the gum between the teeth, 
particularly the lower front teeth. 
They can also be easily used upon 
the sides of the roots of many 
teeth, being passed toward the 
apex of the root in a line nearly or 
quite parallel with that of the 
axes. No. 5 is intended to be 
passed between the lower front 
teeth at or near the gum and 
then directly upward, to remove 
the deposits on the proximal sur- 
faces. No. 6 is a hoe, and is in- 
tended to be passed quite to the 
apex of the roots, where a hoe is 
desired. 



Subgingival Deposits. 

Definition. — By subgingival de- 
posits are meant calculi which are 
first deposited in the annular de- 
pression between the gum-margin 
and a tooth. They are harder, 
smoother, and much darker than 
common salivary calculi, and collect in much smaller masses ; 
they are not found upon the crowns of the teeth, their encroachment 
being in the direction of the cementum (Fig. 353). 

Composition. — So far as imperfect analyses have shown, these 



SUBGINGIVAL DEPOSITS. 



457 



Fig. 353. 



deposits are composed of calcium phosphate combined with undetermined 
organic substances. 

Occurrence. — The cavity in which they are found is open to the 
saliva. They are associated with marginal gingivitis, being found after 
a marginal catarrhal condition has been established, and before any 
direct evidence of degeneration of the pericementum is observed. So 
far as clinical observations can indicate, their formation is in consequence 
of the gingivitis ; the primary causes of the deposit are, therefore, the 
causes of marginal gingivitis, both predisposing and exciting ; these 
causes have already been discussed. Following the general rule of cal- 
culus-formation, the source of the deposits would be, then, the precipi- 
tation of the calcium salts of the saliva into the inspissated or coagulated 
altered secretion due to the catarrhal disturbance. 

Effects. — The direct effects of the deposits are those of a persistent 
foreign body, a mechanical irritant in contact with vital tissue. The 
remote effect depends upon whether any of the causes recognized as pre- 
disposing to pericemental degeneration exist, such as anaemic, leukaemic, 
conditions ; disuse, misuse, or overuse of 
the teeth, nephritic or arthritic disorders. 
Any and all predispositions in this direc- 
tion, it will be recognized, are noted in that 
period of life known as the degenerative 
period, beginning in most persons after 
the fiftieth year ; minor evidences of the 
advent of this period may be seen as early 
as thirty years of age, or even sooner. 
Predisposing causes, any of those named, 
existing, and active causes of gingivitis 
arising during this period of degeneration, 
thirty to fifty years : the calculi form, and 
incite degenerative changes in the perice- 
mentum, attended by a more or less constant set of symptoms, consti- 
tuting a condition known as pyorrhoea alveolaris, better known in 
America as Rigg's disease. During the progress of pericemental 
destruction a fourth type of calculus makes its appearance, scattered as 
small islets over those portions of the tooth-root denuded of peri- 
cementum (Fig. 368). 

Predispositions to pericemental degenerative changes may manifest 
themselves in limited atrophies. Unaccompanied by inflammatory 
symptoms, and by no evidences of local irritation, the normal-looking 
gums may recede from about the necks of the teeth, exposing a variable 
amount of the cementum ; in molars the point of root-bifurcation is 
frequently exposed. The shrinkage of the gum may be confined to the 




A, subgingival calculus ; B, receding 
pericementum. 



458 PERICEMENTAL DISEASES BEGINNING AT THE GUM-MARGIN 

labial and buccal faces of the teeth, or the lingual aspects may also be 
involved. An atrophy of the alveolar margins has occurred and the 
point of pericemental attachment becomes progressively higher. This 
atrophy may affect one or more of the teeth. It is of frequent occur- 
rence when the adjoining tooth or teeth have been lost, and the normal 
resorption of the alveolar walls at the points of extraction is not 
limited to these sites, but involves the alveolar wall of the tooth 
adjoining, and at but one aspect. The process is most marked in the 
lower second bicuspids after the molars have been lost. Secondary and 
more rapid degenerative changes may succeed the slowly advancing 
atrophy at any stage of its progress. 



CHAPTER XXV. 
PYORRHCEA ALVEOLA RIS. 

While the term pyorrhoea alveolaris implies but one symptom 
common to several distinct varieties of disease of the pericementum, 
that of a flow of pus from the alveolus, it is generally understood as 
a term descriptive of degenerative conditions which have some distinc- 
tive features ; these are a progressive loosening of the teeth attended by 
a loss of the retentive structures, alveolar walls and pericementum, the 
loosening of the teeth being in a majority of cases attended by a flow 
of pus from the affected alveolus, and by deposits of calculi upon the 
denuded roots. The disease ceases spontaneously with the loss of the 
teeth ; the resorption, loss, or atrophy of the alveolar wall being arrested 
at any period of the disease, if the affected tooth be extracted. 

All of the varieties of this disorder, of which there are at least 
three clinical types, are associated with all of the predisposing and 
active causes of degenerations of the pericementum, and are most com- 
mon from the age of thirty onward, although the disease may in excep- 
tional cases appear during childhood, notably in rachitic patients. 

Attempts to include all cases of tooth-loss, characterized by the 
features above named, into one class, based upon the pathogenesis of 
the disease, have thus far signally failed, and have done much to 
increase the confusion already associated with theories as to definition, 
causes, prognosis, and treatment of clinical cases. 

Disposition has not been wanting to assign a specific form of infection 
as the causative element of this peculiar mode of tooth-loss, but thus 
far the attempts have been unsuccessful, although in all cases where 
pus-formation is found the pyogenic staphylococci and streptococci are 
undoubted attendants. Miller's experiments in this direction l failed 
to isolate any specific bacterium. He quotes largely from other experi- 
menters, notably Galippe and Malassez, whose researches in the same 
field were all indeterminate. 

Leaving aside questions of direct and remote causation, the cases 
may be clinically divided into three classes : 

First, cases associated with and arising from a primary gingivitis, 
with the formation of hard, scaly, dark, annular calculi beneath the 
gum-margin. 

1 Micro-organisms of the Human Mouth. 

459 



460 PYORRHCEA ALVEOLARIS. 

Second, cases in which gingivitis may not be marked ; the early 
deposits may be entirely absent ; the necrosis of the pericementum 
advances in such a manner as to warrant the designation of Black — 
phagedenic pericementitis. 

Third, cases in which the degeneration and necrosis of the peri- 
cementum and deposits of calculi occur upon some lateral aspect of a 
tooth-root, the gum-margin being apparently normal. 

The differentiation between these several conditions is important, 
because while all three exhibit some features in common, they differ as 
to causes, clinical histories, prognosis, and mode of treatment. In the 
first class pericemental degeneration appears to be a secondary feature ; 
in the second the distinguishing feature ; and in the third degeneration 
and death of a circumscribed portion of the pericementum constitute the 
first evidence of the developed disease. They all agree in having the 
diseases of suboxidation as general predisposing causes of their occur- 
rence ; notable among which are the morbid conditions included under 
the head of the gouty diathesis ; the last differs from the others in 
having a gouty condition as the probable exciting cause of the disease. 

Pyorrhcea Alveolaris beginning as a Marginal Gingivitis. 

Causes. — The causes of this condition are both predisposing and 
exciting. The predisposing causes are the causes, both general and 
local, of marginal gingivitis (which see), and the causes which give 
rise to debility of the pericementum — overuse, misuse, and disuse of 
the teeth. 

The exciting causes are, first, those of marginal gingivitis ; secondly, 
deposits of calculi ; thirdly, infection of the irritated tissues. At later 
stages of the disease other factors enter into the case and modify its 
progress ; viz., looseness of the tooth and death of the pulp. 

Symptoms and Clinical History. — The symptoms of the disease 
differ at the stages of its progress. As a rule, the disorder is most com- 
monly seen after its first stages. The first stage is a marginal gingivitis ; 
the gum-margin is swollen oedematous, and reddened ; the extent of the 
swelling and discoloration varies with causes and individuals. In some 
cases the swelling may be pronounced and the gum purplish in color ; 
in others swelling and discoloration may be but slight. At a later 
period an instrument passed beneath the gum-margin may detect the 
presence of a scaly collection of dark-green calculus, partially enclosing 
the neck of the tooth. Cases are seen where the formation of this cal- 
culus appears to have preceded any evident morbid condition of the 
gum. In many cases the hypersemic condition of the gum -margin 
appears to lessen after a smooth calculus has formed. Apparently the 
calculus has formed in consequence of the union between the calcium 



PYORRHEA ALVEOLARTS (FIRST CLASS). 



461 



salts of the saliva and the inflammatory exudations, the vascular condi- 
tions afterward subsiding. Infection and swelling of the gum are, how- 
ever, the usual condition. The swelling and discoloration persist ; the 
calculus-formation encroaches further upon the pericementum, and the 
root becomes progressively denuded. As a rule, a recession of the line 
of the alveolar process is constant with the degree of root-denudation. 
At any period, and usually early, evidences of infection appear; pus 
may be pressed from beneath the gum-margin. Except in the later 
stages, or unless pus is confined, it is unusual to find the tooth particu- 
larly sore upon percussion. When about one-half or more of the root 
has been stripped of pericementum and deprived of alveolar support, 
looseness and extrusion of the tooth become marked. The teeth are 
nearly always looser than normal, even in the early stages. 

The advance of the disease now becomes more rapid ; the undue 
mobility of the tooth excites an inflammatory reaction beyond the 
directly infected part, so that soreness and looseness are further in- 
creased. A scaler passed into the pocket formed between the gum 
and tooth will now usually detect marked roughness of the root. If 
the latter be scraped, small, hard, nodular deposits of calculi are 
detached with difficulty. After the looseness of the tooth becomes 
marked, the pulp of the tooth is usually killed by strangulation of its 
vascular supply. Infection of the dead pulp readily occurs, and septic 
apical pericementitis arises. The symptoms of the latter condition 



Fig. 354. 



Fig. 355. 





Section of an upper molar with its alveolus, 
etc., showing deposit of serumal calculus 
under the gingival borders ; a, a, serumal 
calculus. (Black.) 



Section of an upper incisor, showing at 
a, a, a deposit of serumal calculus 
within the free margin of the gum. 
(Black.) 



are modified, according to the facility with which the pus finds vent 
along the degenerating pericementum. The disease proceeds until the 
affected tooth or teeth are cast out, the alveolar walls and pericementum 
having entirely atrophied. The disease ceases with the loss of the 
affected teeth, leaving a flattened or absent alveolar ridge covered by a 



462 



PYORRHCEA ALVEOLARIS. 



Fig. 356. 




mass of more or less spongy gum-tissue. The duration of the disease 
may be months or years. 

A general subcatarrhal condition of the mouth usually attends the 
disease. 

Pathology and Morbid Anatomy. — Figs. 354, 355, and 356 exhibit 
three distinct relationships of this form of calculus. Present data 
relative to the pathology and morbid anatomy of all three classes 

of pyorrhoea have been derived from clinical 
observations of teeth in the mouth and 
from an examination of teeth which have 
been lost at some period of the disease. 

The Teeth. — In all of the varieties of 
pyorrhoea it is the general rule to find the 
teeth singularly free from dental caries. In 
a majority of cases their forms are of a type 
considered characteristic of the bilious and 
the nervous temperaments — broader at the 
occlusal surfaces and cutting-edges than at 
the necks of the teeth. Upon section all 
of the deutal tissues are seen to be of a 
highly organized type ; they offer unusual 
resistance to cutting-instruments. The 
enamel has a flint-like hardness, the den- 
tin is much increased in translucency, 
and the pulp-chamber is much contracted — i. e., the formative activity 
of the pulp has been carried to its extreme limit. The pulp-tissue is 
increased in density, and there is a notable increase in its fine fibres. 
One section exhibited an apparent loss of odontoblasts (atrophy) over a 
considerable surface of the pulp-periphery ; others of these cells were 
reduced to comparative flatness. This, however, was a clearly gouty case. 
The appearance of the root depends upon the stage of the disease 
when the tooth was lost. In the early stages a band of dark, smooth, 

scaly calculus surrounds a portion of the 
neck of the tooth, and embraces the ce- 
mentum, slightly overlapping the enamel. 
Beyond the calculus is an area of denuda- 
tion, the cementum free from pericemen- 
tum ; beyond this, the pericementum is in- 
tact, but its fibres are swollen, and its color 
deepened. The presence of a ring of bare 
cementum between the pericementum and 
the calculus was constant in all of the specimens examined. The infer- 
ence is that after the primary deposit, necrosis of pericementum precedes 



Section of an upper incisor, showing 
at a a deposit of serumal calculus 
and destruction of the lower bor- 
der of the alveolar wall and peri- 
dental membrane, with a slight 
recession of the gum, exposing the 
calculus. (Black.) 



Fig 




b— 



A, thickened pericementum ; B, sub 
gingival calculus. 



PYORRHCEA ALVEOLARIS (FIRST CLASS). 



463 



subsequent deposits. Teeth extracted at later periods exhibit usually two 
varieties of calculus : first, that which formed beneath the gum-margin ; 
second, beyond, upon the denuded cementum, are small islets, bead-like 
deposits of rough, hard, dark calculi, which appear also in other dental 
conditions attended by continued pus-formation. They appear identical 
with the deposits which are found upon the apices of roots in long-con- 
tinued chronic septic apical pericementitis (alveolo-dental abscess), and on 
the sides of roots in cases of the same disease discharging at the gum- 
margin, in cases of phagedenic pericementitis, and as secondary deposits 
in gouty pyorrhoea. Their association with chronic pus-formation 
appears clear, their presence being evidence of continued suppu- 
ration. They are to be regarded as resultant from, not causative 
of the pericemental degeneration. They are more often present in 
cases of delayed than in rapid tooth-loss. Teeth extracted at the latest 
stages of the disease show that the apical pericementum still maintains 
attachment, and is much swollen. Examining the tooth or teeth before 
they are extracted, a pocket is found to exist beyond the calculus, and 
its direction and situation ' depend upon the position of the calculus. 
If this be, as it frequently is, upon the palatal surface of the root, the 
formation of a pocket at the labial aspect may not be marked until the 
posterior pocket is much deepened. 

In most of the cases of the first class of pyorrhoea a probe fails to 
discover uncovered alveolar bone, although it may do so ; a matter of 
some importance, as it indicates in some measure the mode of alveolar 
degeneration. If the bone be covered, 
its resorption is more of the nature of an 
atrophy ; if uncovered, it is probably 
lost in part through peripheral molecu- 
lar necrosis. The conditions point to a 
progressive recession of the pericemen- 
tum, with the loss of alveolar wall, as 
an atrophy, a secondary process. 

It is to be remembered that all evi- 
dences of alveolar disease cease promptly 
with the loss of the affected teeth. 

A condition sometimes met with is 
recorded by Black, in which a dual peri- 
osteal disease is in evidence (Fig. 358). 
The irritation caused by the presence of 
a subgingival deposit has resulted in an 
atrophy of the immediately adjacent alveolar process ; at the labial 
aspect of the alveolar edge the pericementum has been irritated to a 
constructive stage and a new deposit of bone has occurred, resulting in 



Fig. 358. 




Section of an upper incisor, showing de- 
struction of the peridental membrane 
and eversion of the alveolar wall, 
with thickening of its border : a, seru- 
mal calculus; b, thickened border 
of the alveolar wall; c, pus-cavity. 
(Black.) 



464 PYORRHCEA ALVEOLARIS. 

a distinct thickening of the alveolar margin. This condition illustrates 
well the effects of grades of irritation ; how one grade is productive of 
increased functional activity, another of degeneration and atrophy. It 
is rare for this variety of pericemental destruction to proceed to any 
considerable depth without abundant manifestations of pyogenic infec- 
tion. The infection, however, exhibits no disposition to invade the 
outer maxillary periosteum ; it follows the direction of the pericemen- 
tum, and ceases promptly as soon as the teeth are extracted, no matter 
at what period. 

Diagnosis. — Usually but little difficulty attends the diagnosis of 
this varety of pyorrhoea. As a rule, several teeth are affected ; those in 

in which the characteristics of the dis- 

G ease are most marked are the upper 

/ v incisors. If the disease is fully es- 

/ \ tablished, it will be confounded with 

^^^^ U^^^^^^^ ^^ no other condition : the tumid gum, 

'BII^PipPlEMB l^^gagi t the presence of easily discoverable 

/7\f^tp^ ~ T ~f* ^W^f^f] calculi in a subgingival pocket, and 

II If |P If IP I jy ^ e oozm g °f P us > a ^ furnish a clin- 

— kL^iiUi^ i ca l picture not associated with any 

Absorption of the septum of bone and re- other dental disorder. The occur- 

cession of the gum between the central _ 1 . 1 .. 

and lateral incisors, caused by deposits rence ot these pericemental degenera- 

of serumal calculus under the gingiva t fo ng can ^ e foreshadowed at times. 
(Black.) 

In any of the three forms, evidences 
of marginal atrophy of the alveolar walls may be noted before any 
deposits of calculi can be detected, or before there are any indications of 
the initial gingivitis ; the septum of gum between the teeth recedes, 
obliterating the normal gum-festoon (Fig. 359). 

The existence of a persistent gingivitis, with an exaggeration of the 
space between tooth and gum-margin, means a future pyorrhoea. 

Differential Diagnosis. — In the later stage care will be nec- 
essary to determine which variety of pyorrhoea is present. In the first 
variety the bottoms of the pockets are usually found, not far be- 
yond evident deposits of calculi. Indications of the existence of an 
annular alveolar wall are also observed. Gingivitis keeps pace with 
the loss of pericementum. In phagedenic pericementitis the deposits 
may only be recognized, with difficulty ; the degeneration proceeds in 
a direct line toward the apex of the root ; the pericementum may still 
be attached along the other portions of the root ; the gingivitis may 
be very slight ; the gum-edge although receded, may retain its normal 
festoon. In gouty pyorrhoea (proper), deposits about the neck of the 
tooth are unusual, and, except in later stages, the gingival attachment 
appears almost normal. A slender instrument is passed with some 



PYORRHCEA ALVEOLARIS (FIRST CLASS). 465 

difficulty beyond the gum-margin ; its introduction may, again, be entirely 
resisted. Pressure upon the tooth shows it to be loose, and pressure 
over the gum near the apex may show a boggy softness due to an out- 
lined loss of alveolar wall. The family and personal history is of 
great importance. 

In gouty pyorrhoea, and in phagedenic pericementitis but few teeth 
are attacked at once, as a rule ; frequently but one tooth is affected ; in 
the first variety several teeth are affected simultaneously. 

Prognosis. — Of all the varieties of pyorrhoea, the first is that having 
the most favorable prognosis. If properly treated medicinally and me- 
chanically, proper directions given the patient, and frequent super- 
vision exercised, the disease may be arrested in any but its latest stages. 
If predispositions to pericemental degeneration exist, they will modify 
the prognosis in the degree of the difficulty of eliminating them. The 
assertion is made by many practitioners that in their hands pyorrhoea 
alveolaris is an entirely curable disease. These assertions refer, no 
doubt, to the first class, for, as will be seen, the prognosis of the second 
and third classes of pyorrhoea may be independent of therapeusis. 

Treatment. — From the point of view of therapeutics, several condi- 
tions exist in the morbid phenomena described. First, infection ; 
second, the presence of foreign bodies ; third, teeth in any degree of 
partial luxation; fourth, mal-occlusion ; fifth, vascular disturbance of 
the gum and pericementum ; sixth, probably an underlying constitu- 
tional predisposing cause. Treatment is directed, first, to a removal of 
all sources of irritation. The sources of offence are to be removed in 
the order of their danger to the teeth. If the disease have progressed 
far, the imminent danger is mechanical clislodgement of the loosened 
teeth ; the affected tooth is to be lashed to its firmer neighbors, so that 
it is immovably held. A careful examination is next made of the 
occlusal relations ; in the majority of cases the occlusion will be found 
excessive. The teeth and in some cases their an- 
tagonists are ground away by means of corundum 
wheels until they are slightly short of occlusion. 
The exposed portions of the crowns and roots are 
scaled free from all deposits. As it will be neces- 
sary to hold the affected teeth immovably during 
the period of healing, the nature of the splint required 
is determined upon. If but two or three anterior 
teeth are to be held, rings made of thin platinum 
plate form effective splints (Fig. 360). The teeth 
to be splinted are ligated firmly together at their necks, and a strip 
of platinum plate, Xo. 34, is annealed and moulded against the lingual 
faces of the teeth ; it is passed between the teeth to be splinted and 

30 





466 



PYORRHCEA ALVEOLARIS. 



Fig. 361 




those posterior, and its free ends are overlapped ; a scratch is made to 
indicate the overlap, and the piece is detached and soldered. Returned 
to the teeth, the thinnest separating saw is passed between the teeth, groov- 
ing the splint deeply upon both sides ; in these grooves straight strips of 
platinum plate are placed. If the piece can be lifted from the teeth 
without force, it is so displaced ; if not, a plaster impression is taken, 
a cast of investing material made, and the strips soldered in their 
grooves. The investment and splint are thrown hot into sulfuric acid, 
which cleanses the splint and removes the investment without force. 
The splint is washed in running Avater, the teeth are wiped off with 
chloroform, and the splint cemented in place with zinc phosphate. 

Where several teeth are to be held a swaged plate is usually the 
most effective splint. After the occlusion has been overcorrected, a 

plate to cover the loose and the immediately 
adjoining teeth is swaged and cemented to the 
teeth (Fig. 361). 

The operator's ingenuity will show him 
which of the great number of retaining appli- 
ances devised will serve best in a particular 
case. Many of the retainers used in ortho- 
dontia serve admirably as splints. The splint 
in position, surgical rest is assured. The agent second in import- 
ance, as threatening the pericementum, is the infection. Antiseptics 
are to be freely used during all operations and frequently by the patient 
after, and between operations. The pockets are first freely syringed or 
sprayed with hydrogen dioxid until effervescence ceases ; wisps of 
cotton dipped in 25 per cent, pyrozone are next placed in the pock- 
ets (Ottolengui) ; a white eschar forms 
at once, and any pus or decompos- 
ing organic matter remaining is de- 
stroyed. The next threatening element 
is the calculus ; so long as deposits of 
calculi remain, irritation will continue. 
Beffinnin^ with the tooth most threat- 
ened, delicate scalers (Fig. 362) are 
passed beneath the gum, and used 
with a push cut to chisel away all depos- 
its. The instruments must be delicate 
in order to detect the granule-like 
deposits. The cutting is to be firm 
and decided, but slipping of the instru- 
ment must be guarded against by rest- 
ing the fingers upon the tips of the teeth (Fig. 363). The scraping is 



Fig. 362. 




Showing the application of a thin, flat 
instrument to the labial and approxi- 
mal surfaces of an upper bicuspid 
(pushing motion). 



PYORRHCEA ALVEOLARIS (FIRST CLASS). 



467 



alternated by syringing with hydrogen dioxid to cleanse the pockets. 
If much swelling of the gum be present, tampons of cotton saturated 
with 10 per cent, solution of trichloracetic acid packed in the pockets 

Fig. 363. 




Showing the manner of holding an instrument for detaching calcareous deposits when using the 
pushing motion. The third finger rests on the edges of the teeth, allowing freedom of the 
hand to make rapid and effectual movements in dislodging the calculi. 

for a few minutes will check oozing and permit a better view of the 
pockets. 1 The scaling of one tooth is to be completed before passing 
to a second tooth. This, however, does not apply to the first visit after 
splinting the teeth ; as it is frequently advisable to then remove the 
coarse subgingival deposits from all of the teeth, cleanse the pockets 
with 25 per cent, pyrozone, and prescribe an astringent antiseptic 
mouth -wash to be used several times daily for two or three days : 



1^. Zinc chlorid, 
Aq. menth. pip., 



gr. x ; 
5J.— M. 



The tumefaction of the gum will be much reduced and pus-formation 



Kirk. 



468 PYORRHCEA ALVEOLARIS. 

checked by this means. At the second visit the scaling should be begun 
and continued upon a tooth until it appears entirely free from roughness 
before passing to a second, and so on. Partial scaling, repeated at inter- 
vals, interferes with or prevents the regenerative process. After each scal- 
ing the pockets are syringed forcibly with hydrogen dioxid. The use of 
acids, particularly two of the organic acids — trichloracetic (Kirk) and 
lactic (Younger) — is advised ; they have been found serviceable as an 
application after scaling and syringing. They act as solvents upon 
the minute calculi which escape the scaler, and as caustics, stimulating 
healthy action in the ulcerous pericementum. Unless pus-formation or 
congestion persist, the scaled teeth are to remain undisturbed. After 
the operation, the use, several times a day, of the astringent and anti- 
septic mouth-wash given above is advised. 

Truman advises the use of hydronaphtol in an astringent vehicle 
as an effective germicide for use by a patient : 

3^. Hydronaphtol, g r -x; 

Glycerol, 3j ; 

Alcohol, 5J ; 

Aq. destill., Zi}— M. (Peirce.) 
S. Use as wash several times a day. 

In case of recurring or persistent pus-formation the pocket should be 
again explored, cleansed and dressed as described. 

The splints are to remain in position until the gum appears to grasp 
the teeth firmly, is of normal color, and pockets have closed. If more 
than half of the root has been denuded, permanent splints are advis- 
able. Regeneration of alveolar process does not occur ; the gum gradu- 
ally shrinks to its normal relation with the process in its atrophied 
condition. 

Constant care upon the part of the patient, both as to general and 
oral health, and occasional inspection by the operator are necessary for 
even reasonable assurance against a recurrence of the disease. Recur- 
rence is more or less probable, no matter what precautions are taken. 
Even when pus- and calculus-formation are not re-established, atrophy 
of the alveolar process is common. The advent of these diseases ex- 
presses a degenerative impulse against which the best of therapeusis 
frequently fails, almost entirely. 

Phagedenic Pericementitis. 

The term phagedenic pericementitis was suggested by Black to desig- 
nate a condition whose most prominent feature is a progressive death of 
pericementum, beginning at its marginal attachment, not caused by me- 



PHAGEDENIC PERICEMENTITIS. 469 

chanical injury, chemical agencies, specific virus, or the selective action of 
drugs ; and whose usual, although not constant, accompaniments are 
pus- formation and deposits of calculi. Its progress is phagedenic, and 
ceases with the loss of the tooth. From the pus-flow this disease has 
been included under the generic head of pyorrhoea alveolaris, although 
it is clearly distinguished from the disease already described as due 
primarily to subgingival deposits. 

Definition.— In light of present data phagedenic pericementitis may 
be defined as a condition which comprises degeneration, atrophy, and 
molecular necrosis of the alveolar process and a molecular loss of peri- 
cementum, accompanied in its developed state by pyogenic infection and 
usually by deposits of nodular calculi. The pericementum and alveolar 
process covering a root may be entirely destroyed without any distinct 
evidence of inflammation, suppuration, or calculus-formation. 

Causes. — The causes of this condition appear to be divisible into 
predisposing and exciting. The predisposing causes are those named 
as productive of pericemental debility and degeneration. Among 
the general predisposing causes are heredity, particularly as to 
arthritic diseases, and the diseases of suboxidation and faulty elimina- 
tion. Among the local predisposing causes are overuse, disuse, and 
misuse of the teeth. Overuse and misuse often act as direct excit- 
ing causes. The primary gingivitis noted as inviting the first variety 
of pyorrhoea alveolaris, appears to play a subordinate part in the causa- 
tion of phagedenic pericementitis, although it does usher in the disease 
in some cases, when a deposit of subgingival calculus appears to act as 
the exciting agent of the degeneration. 

Symptoms. — It has been maintained that this disorder is essentially 
infective, but thus far all attempts to discover organisms which are 
pathognomonic have failed. It is more than probable, however, that 
future studies will discover in bacteria an acute etiological factor in 
the disease. The symptoms most characteristic and distinctive of this 
disease are best noted upon an upper central incisor, and others upon 
the palatal root of an upper molar. At a period antedating any evi- 
dences of pericemental affection a tooth, frequently an upper incisor, 
shifts its position, moving outward, or rotat- 
ing and separating from one of its neighbors 
(Fig. 364). There is no peculiarity of the 
occlusion which will explain this shifting. 
At a later period — it may not be for many 
months — the shifted tooth is seen to be 
looser than its neighbors. This loosening 
is hastened if, in shifting, a condition of 
mal-occlusion is established. Before the tooth loosens, evidences of 




470 



PYOBBHGEA ALVEOLARIS. 



atrophy of the alveolar margins may be seen in a recession of the gum- 
festoon between the teeth. As soon as looseness is marked, evidence of 
pericemental loss may be detected by passing an instrument beneath 
the gum-margin, which is seen to be detached at some point, commonly 
between the teeth where the gum-recession was first noted, or at the 



Fig. 365. 



Fig. 366. 





Illustration of a case of phagedenic pericemen- 
titis : a, a, dotted lines representing the out- 
lines of the roots of the teeth ; b, b, irregular 
lines representing the extent of the destruc- 
tion of the peridental membrane and walls 
of the alveolus. It will be noted that the 
gums appear nearly perfect. (Black.) 



The same case shown in Fig. 365, denuded 
of the soft tissues to show more plainly 
the loss of the walls of the alveolus. 
This drawing was made after raising a 
semicircular flap of the soft tissues 
over each root for the purpose of thor- 
ough exploration. (Black.) 



labial aspect of the root (Figs. 365 and 366). While the gum-margin 
usually presents signs of irritation, it may be apparently unaffected. 
If gingivitis be, or have been, present, subgingival calculi will prob- 
ably exist. Exploration of the pockets will show them to be the conse- 
quence of death of pericementum, which has followed the length of this 

structure along the side affected ; the 
remainder of the pericementum and 
alveolar process may be intact. The 
root may exhibit no roughness what- 

Fig. 368. 



Fig. 367. 





A, calculi of pyogenesis ; B, ulcerous A, thickened pericementum ; C, subgingival calculus ; 
pericementum. B, calculi of pyogenesis. 

ever. A careful exploration usually shows a portion of the atrophying 
alveolar wall over the necrotic area to be denuded ; the pericemental 
death has proceeded more rapidly than alveolar atrophy. The pockets 
increase in size, and the alveolar process disappears until the teeth can 
be extracted with the fingers. It is unusual for the pockets to attain any 
considerable depth before evidences of pyogenic infection occur ; so that 



PHAGEDENIC PERICEMENTITIS. 



471 



pus may usually be pressed from the pockets. In cases where pus-dis- 
charge is present, the small nodular calculi may be detected upon the 
roots. 

When pericemental destruction has involved the apical pericementum 
death of the pulp occurs, and infection of the necrosed pulp results ; 
abscess forms and pus discharges via the pyorrhoea pocket. 

When the disease attacks but one root of a molar, destruction of the 
pericementum around that root, death of half of the pulp, and abscess- 
formation may result, and the other roots be unaffected ; a portion of 
the pulp of the tooth may retain its vitality for some time, notwithstand- 
ing the apical abscess upon one root. In these cases pus-discharge 
from about the root of a tooth may be continued by the infected dead 
pulp, after all pericementum and alveolar process are gone from about 
the root. 

While the disease is usually first noted about a single tooth ; it is 
rare that a lengthened period elapses before it makes its appearance 
about other teeth ; usually an adjoining tooth, or, it may be, on a distant 
one. This disease may make its appearance in the mouths of patients 
who take extraordinary care of the teeth, in mouths where the teeth 
are apparently entirely free from deposits, where the gum appears nor- 
mal, and where the teeth are free from caries. It is of more frequent 
occurrence in dentures comparatively free from caries than in those 
where caries prevails or has prevailed. 

Morbid Anatomy and Pathology. — Teeth lost through this disease 
may exhibit no abnormal appearances at all, except the entire absence 



Fig. 369. 



Fig. 370. 





Fig. 369.— Section of upper incisor, showing destruction of its peridental membrane and alveolus 
by phagedenic pericementitis : a, gum-tissues covering pus-cavity (6) formed by the destruc- 
tion of the peridental membrane and alveolar wall. (Black.) 

Fig. 370.— Section of an upper molar, showing destruction of its membrane and alveolar wall by 
phagedenic pericementitis : a, deposit of serumal calculus ; b, b, gum covering pus-cavity (c, c) 
formed by the destruction of the peridental membrane and alveolar wall. (Black.) 

of even shreds of pericementum. They may be entirely free from all 
deposits. The teeth are nearly always of the type assigned to the bil- 



472 



PYORRHCEA ALVEOLARIS. 



ions and sanguine temperaments, and are singularly free from dental 
caries. The enamel of the teeth may be abraded in some degree, in 
which case the areas are seen to have a glossy polish. Upon section 
enamel and dentin are seen to be of the highest type of organization. 
The pulp-chamber is much contracted. Data are wanting relative 
to the condition of the pulp in these cases ; but it is inferred from the 
condition of the pulp-chamber, and the age at which the disease makes 
its appearance, that atrophic changes are probably present. 

An examination of alveoli and pockets will show two types of the 
disease : those affected by the subgingival deposits and those without 
(Figs. 369 and 370). The root is denuded of pericementum to an un- 
usual depth, and the edge of the alveolar process is found to be bare. 
A pocket may extend to the very apex of the root upon one side of a 
root, and the attachment upon the opposite side remain normal for a 
long period (Fig. 371). The alveolar septum between two adjoining 
teeth may be destroyed together with the corresponding portions of 
pericementum, and the remainder of pericementum upon both teeth 
remain intact for a long period. In cases without deposits an absence 
of gingivitis is frequently noted ; even more, an atrophy of the gum- 
tissue occurs which bares to some extent the denuded root. Where 
subgingival deposits are present, gingivitis is the rule. The effects 
of the occurrence of constructive pericementitis upon the outer alveolar 
margin may be noted in some of the long-continued cases. 

Fig. 371. 




Showing loss of pericementum and alveolar process over one face of one root of a molar tooth from 
phagedenic pericementitis. Several of the other teeth were the seat of the first variety of 
pyorrhoea. 

What was said of the first variety of pyorrhoea, relative to the loca- 
tion of the disease, applies with equal force to phagedenic pericemen- 
titis. It is a disease of the pericementum, and alveolar necrosis is a 
secondary feature, which ceases as soon as the teeth are lost by extrac- 
tion or by the progress of pericemental necrosis. There is an atrophic 
variety of the disease which exhibits peculiar features. Marginal alveo- 
lar atrophy is seen to occur about the roots of several teeth. There 
is no vascular disturbance in the gum-tissue, so that the gum-line 



PHAGEDENIC PERICEMENTITIS. 



473 



recedes with the alveolar wall. The cementum of the root becomes 
exposed almost always at the labial or buccal aspects. Later, death of 
an annular portion of pericementum and infection by pyogenic organ- 
isms occur ; immediately beneath the gum-margin small, hard, nodular 
calculi are formed. Instead of deep pockets, the pericemental loss is 
attended by a constant recession of the gum-line until the roots of 
the teeth become exposed for a great part of their length ; the reces- 
sion of the gums exposes the calculi which have formed (Fig. 372). 

Fig. 372. 




The alveoli irreparably destroyed by calcic inflammation. (Black.) 

This process is far from uncommon in the mouths of persons who pos- 
sess fine dentures, but who neglect the care of their mouths. 

Diagnosis. — The differential diagnosis of phagedenic pericementitis 
from the first and third varieties of pyorrhoea has been given in 
connection with the first variety. Its direct diagnosis consists in dis- 
covering the peculiar pockets, denuded roots, and alveolar edge. Its 
occurrence can almost be certainly foretold in the mouths of patients 
who have fine dentures of the type described, who have particularly an 
arthritic history, and who, about the age of thirty or later, note the 
change of position of one or more teeth without evident cause. It will 
be recalled that the pockets in phagedenic pericementitis have a depth 
out of all proportion to their lateral extent. 

As pointed out by Black, the condition may be confounded with 
apical abscess opening along the side of a root. If the latter be acute, 
the acute symptoms of alveolar abscess, absent in phagedenic perice- 
mentitis, point to a diagnosis. If chronic, there may be noted evi- 
dences of pulp-death, absent response to thermal stimuli, and the pres- 
ence of large fillings. An examination should be made of the other 
teeth, for it is unusual that phagedenic pericementitis will progress to 
the end of the root of a single tooth before other teeth are involved. 
Doubt will be dispelled by opening the affected tooth, whether carious 
or non-carious. If the pulp be alive, it is phagedenic pericementitis ; 
if dead, it may be that or alveolar abscess. If the latter, a cure is 
accomplished by treatment as described in Chapter XXII. 



474 PYOBRHCEA ALVEOLABIS. 

Prognosis. — The prognosis of this disease, so far as the teeth affected 
are concerned, is in general decidedly unfavorable. While it may be tem- 
porarily arrested in its earlier stages, its recurrence and ultimate loss of 
the affected teeth are the rule. It may attack but few teeth of a denture 
and progress until they are lost, the other teeth remaining unaffected. 
The common history, however, is that when the disease makes its appear- 
ance the denture is ultimately lost through it, although the period of loss 
may cover many years. Several years may elapse between the loss of 
one tooth and the affection of the second. Upper incisors and molars 
appear to suffer more frequently from the disease than any of the other 
teeth. 

Treatment. — Treatment of the case, based upon the relief of dis- 
coverable morbid conditions, will serve to stay the process. The con- 
ditions demanding correction are, faulty occlusion, undue mobility, the 
presence of necrotic tissue, usually an infection and foreign deposits. 
These latter are to be regarded as pathogenic in that they prevent a 
return to health of the gum-tissue overlying them. 

The treatment is both prophylactic and remedial. Patients having 
an arthritic history and the type of denture named should be warned of 
the dangers of establishing a pericemental debility through relative dis- 
use of the teeth, and of permitting morbid gingival conditions to arise 
from neglect of oral hygiene. The relations of food-habit and gen- 
eral disease, notably those of suboxidation, to dental disease are to be 
pointed out. 

In the early stages of pyorrhoea, that of tooth-shifting, it has been 
asserted 1 that, if the tooth be opened, the pulp destroyed, and canal 
filled, the impending degeneration and necrosis of the pericementum 
will be averted. There is good clinical evidence, both of the writers 
quoted and others, to substantiate the assertions. The probable expla- 
nation is that the diversion of the apical blood-supply entirely into the 
pericementum protects this structure against threatened degeneration. 
There is reason to believe, although histological data in this connec- 
tion are wanting, that changes in the bloodvessels and nutrition of 
the pericementum are antecedents to the degenerative and necrotic 
changes described. When the pockets have formed and alveolar 
atrophy is marked the conditions resemble in some particulars, but are 
by no means identical with, those noted in connection with the first 
variety of pyorrhoea. 

The treatment, as regards splinting of the teeth and sterilization of 
the pockets, is the same as in the first class. Black emphasizes two 
points of much importance in the next stage of treatment — i. e., the 
removal of deposits — first, that the gum-margin must not be unnec- 

1 M. L. Khein ; D. D. Smith. 



PHAGEDENIC PERICEMENTITIS. 



475 




Scalers (three times 
natural size). 



essarily injured ; secondly, that vigorous scaling of the roots may be 
done without special regard to avoid cutting the tissues lining the 
pocket, instead of avoiding such injury, as in the 
first class of pyorrhoea. The pockets are freely Fig. 373. 

syringed with hydrogen dioxid, or with a 1 : 500 
solution of mercuric chlorid in hydrogen dioxid. 
The alveolar edges are to be freely scraped with 
the scaling instruments, which should have slender 
stems and comparatively broad cutting-blades (Fig. 
373). The use of cauterants, such as trichloracetic 
and lactic acids, is more important than in the former 
type of disease. The same astringent antiseptic 
washes are to be prescribed. After removing all 
foreign material, including dead matter and steriliz- 
ing, correcting occlusion, and securing immobility, 
the astringent antiseptic wash is expected to draw 
the tissues tightly about the teeth and to prevent infection, so that a 
regenerative process can be established in the vital tissues of the former 
disease-pocket. 

In case the pockets are so deep or have such form that the alveolar 
margins cannot be well trimmed without overstretching or injuring the 
gingival edges, Black advises that gum- 
flaps be raised, exposing the alveolar 
margins (Fig. 374). A semicircular 
incision is made and turned back, and 
bleeding checked. By means of sharp 
chisels the alveolar borders are freely 
scraped, the pockets are flushed with 
hydrogen dioxid, and the flap secured 
by a couple of stitches. The same 
writer advises in cases where eversion 
of the alveolar margin has occurred, that the process be exposed by 
cuts and broken down by three cuts made with a sharp chisel and 
mallet ; the loosened segment of bone to be pressed firmly against the 
root. It is desired next that the entire pocket will fill with granula- 
tion-tissue, and organization of the granulations take place, furnishing 
re-attachment. That this occurs in some cases is undoubted. Black 
believes that a reproduction of alveolar margins also occurs in some 
cases. The hope of good results lies in keeping the parts aseptic after 
all foreign deposits and dead material have been removed. 

A great number of agents have been advised as medicinal applica- 
tions to the disease-pockets. They are all antiseptic and most of them 
cauterants. These are to be used after the primary cleansing. During 



Fig. 374. 




Illustration of the position and form of 
incision through the gum for exposing 
the root of the tooth and injured alveo- 
lar process ; a, incision. (Black.) 



476 



PYORRHCEA ALVEOLARTS. 



the period of granulation no solutions stronger than stimulants should 
be used. A 20 per cent, solution of zinc iodid (Harlan), the hydro- 
naphthol solutions (Truman), and the zinc-chlorid wash primarily given 
may all be taken as representative medicines. The indiscriminate use of 
strong solutions of antiseptics retards the granulating process. The 
silver salts, lactate and citrate, 3 per cent, solutions of silver nitrate, 
and powdered nosophen should be mentioned as useful agents in this 
connection, particularly the silver salts. 

The records of experiments with sponge-grafts are not encouraging, 
there being too great difficulty in maintaining them sterile. 



CHAPTER XXVI. 

DISEASES OF THE PERICEMENTUM BEGINNING UPON A 
LATERAL ASPECT OF THE TEETH. 

Gouty Pericementitis. 

From its common occurrence in persons who are the victims of the 
gouty or arthritic diathesis, a third variety of pyorrhoea alveolaris has 
been designated as gouty pericementitis. 

Definition. — Gouty pericementitis may be defined as a condition in 
which degeneration and necrosis of the pericementum begin in some 
portion of that structure between the apex of a root and the gum- 
margin, usually attended by a deposit of calculus in the disease-area, 
which exhibits a combined reaction of urates and of calcium phosphate. 
As noted in connection with the first and second varieties of pyorrhoea, 
many general diseases included in the family of diseases called gouty, 
act as predisposing factors in their causation. In the third variety, not 
only does a gouty condition act as a predisposant, but it appears to 
furnish also the exciting cause of the disease. 

The pathology and pathogenesis of the disease will be more evident 
after a survey of its clinical history and symptoms, and a review of the 
mode of action of the gouty poison. For many years gout and the 
gouty diathesis have been recognized as causative of a number of local, 
including among them, several dental diseases, periodical dental neural- 
gias, pericementitis, and phagedenic destruction of the pericementum. In 
1886 "W. J. Reese 1 pointed out clearly the association of the gouty condition 
with what he termed " phagedena pericementi." In 1891 J. S. Marshall 
demonstrated the analogy of certain pericemental degenerations with a 
gouty condition. Impetus was given the study of this association when, in 
1892, C. N. Peirce demonstrated that deposits found upon the lateral 
aspect of the pericementum gave a murexid reaction, proving the presence 
in them of urates, the salts found in gouty concretions in other parts 
of the body. He also pointed out that the deposits occurred without 
primary destruction of the marginal pericementum, so that the primary 
disease-focus is found upon some portion of pericementum lying between 
the root-apex and gingival attachment. 

Symptoms and Clinical History. — The symptoms of gouty dental 

diseases depend upon the stage at which they are seen. In the earliest 

stages vague functional disturbances appear before there is any evidence 

1 Dental Cosmos. 

477 



478 DISEASES OF THE PERICEMENTUM. 

whatever of structural changes. Like other gouty affections, dental 
gout rarely makes its appearance before thirty years of age, and most 
frequently between forty and fifty-five years. 

Beginning with the earliest visible evidence of disorder, dental gout 
appears to exhibit itself about as follows : in the mouths of persons 
presenting a clear family history of gout, or of rheumatoid arthritis in 
the female line, who have been the victims of gout, evident or obscure, 
more often the latter, or, again, suffer from the condition called 
"lithsemia" (professional man's gout), it is commonly noted that the 
teeth are singularly exempt from dental caries. This is a general, 
although not universal truth. The teeth are frequently of highly organ- 
ized type, and of the variety said to be indicative of the bilious or 
nervous temperament. Frequently they are the seat of mechanical 
abrasion ; their occlusal faces may be worn to any extent, the character 
of the wearing depending upon the nature of the occlusion ; it is less 
marked in teeth having long cusps than in those having an originally 
short overbite. The long cusps show the spots of enamel-wear as areas 
having a glossy polish. Erosion (which see) is of frequent occurrence 
in such dentures, particularly among females. The dentures are of the 
class in which phagedenic pericementitis is apt to make its appearance. 

In the mouth and about the jaws of such an individual, after the 
age of thirty, neuralgic pains may be of nightly occurrence ; these 
pains are vaguely referred to the teeth. An examination of the 
teeth exhibits no direct reason for their occurrence ; there may be no 
dentin-exposure and no tenderness upon percussing the teeth. It will 
be noted, though, that the response of the teeth to thermal changes is 
decidedly increased : a general heightened sensitivity of the dental pulps 
exists. These pains and the pulp-hypersensitivity disappear after a time. 
In some cases this may be spontaneous ; in others it will be found that 
the patients have been receiving general medical treatment, and the 
maxillary pains disappear with the cure of the disorders treated by the 
general practitioner. At later periods occasional attacks of general 
pericemental tenderness may occur, which make their appearance and 
disappear as did the maxillary neuralgia. In both cases there is a 
return to apparently complete normality. These symptoms are also of 
frequent occurrence in the mouths of patients who suffer from dental 
erosion and abrasion. The exposed dentin in these cases furnishes a 
tangible cause for the reflex pains about the jaws. 

If the teeth be examined after this period, the comparative exemp- 
tion from caries, and usually from calculous deposits, is noted, together 
with the firm fixation of the teeth in dense alveolar process. However, 
a slight recession of the gum-line may be noted, as though a very 
limited marginal alveolar resorption had occurred. Later, periods of 



GOUTY PERICEMENTITIS. 479 

pericemental soreness may be more frequent, and one or several teeth 
during this period are loosened from their former firm implantation. 
The soreness may disappear, but the slight looseness of the tooth may 
remain. 

It is at later periods and in some single tooth, that degenerative and 
necrotic changes become unmistakable. Some one tooth of a denture 
becomes sore and tender upon percussion ; the gum overlying the apical 
half of the root exhibits the evidences of an underlying inflammation. 
The tooth is loosened, but the attachment of the gum-margin remains 
unbroken ; indeed, unless the inflammation be marked there may be no 
evidence of marginal gingivitis. The symptoms closely resemble those 
of acute septic apical pericementitis, although less in degree. The 
inflammation may subside and leave the tooth permanently loose. In 
other cases a circumscribed swelling appears, indistinguishable from that 
of acute apical abscess ; the surrounding inflammation is, however, less. 
If an incision be made into this swelling, a glairy, mucus-like discharge 
may vent ; in other cases a flow of pus is observed. In the latter case 
pyogenic infection is certainly present ; in the other, infection is uncer- 
tain. Many of these cases have been diagnosed as septic apical peri- 
cementitis due to dead pulp : the tooth being probably non-carious, the 
death of the pulp is assigned to one of the conditions described under 
diseases of the pulp. Upon drilling into the tooth dentinal sensitivity 
may appear to be absent, and the instrument may be plunged into a vital 
pulp — i. e., the inflammation and suppuration have no connection with 
a dead pulp. If the incision into the abscess-cavity be enlarged and 
bleeding checked, it will be seen that a portion of the alveolar wall has 
disappeared, exposing the side of the root of the tooth, which is 
found to be denuded of a portion of its pericementum, and on the root 
rough bodies are noted, which if scraped away, are seen to be calculi. 

In some cases the symptoms of pericementitis persist without the 
formation of a circumscribed swelling over the root, and later a discharge 
of glairy, mucus-like material or of pus exudes from beneath the gum- 
margin. The same errors of diagnosis, and discovery of live pulp noted 
above, are frequently made. In other cases the pericemental destruction 
may be so extensive and accompanied by a disappearance of such an 
amount of alveolar process that the teeth are very much loosened. If 
the teeth be non-carious, as they usually are, and the looseness have 
not been marked, an examination of the interior of the tooth shows 
uniformly the presence of vital pulp. Teeth have been extracted 
during this period, one of which exhibited these significant features : 
the apical pericementum was intact, as was also that portion toward the 
gingival margin ; between the two was an area of denudation, in which, 
loosely attached to the root, was a rough, irregular calculus (Fig. 376). 



480 



DISEASES OF THE PERICEMENTUM. 



Calculi scraped from the roots of such teeth exhibit in a varying degree 
a response to the murexid test, the test for urates. The reaction may be 



Fig. 375. 



•SS 




Fig. 376. 




A and C, vital pericementum ; B, gouty calculus ; D, a 
subgingival calculus. 



A, calculus in area of necrosis ; B and 
C, vital pericementum. 



very faint in some cases, being overshadowed by the calcium phosphate, 
which makes up the bulk of these masses ; in others it is pronounced — 
i. e., urates make up a portion of the deposit. 

A significant feature is that in the irritative and inflammatory stages 
of the disease, except in those where pus forms, if the patient receive 
vigorous anti-gout treatment, the dental inflammation subsides. 

While pericemental irritation may involve many teeth, acute out- 
breaks are usually confined to but one or, at most, two teeth. The 
disease subsequently attacks other teeth singly, although these may 
escape involvement for years. 

Diagnosis. — The symptoms and clinical history given clearly dif- 
ferentiate this condition from the pyorrhoea due to subgingival deposits 
and phagedenic pericementitis. When, however, the discharge of pus 
at the gum-margin occurs the case may be indistinguishable from 
phagedenic pericementitis ; the difficulty of differentiation is all the 
more increased from the fact that both occur in patients affected by the 
same classes of general disorders. In phagedenic pericementitis, however, 
some local explanation of the disease-process may be elicited ; in gouty 
pyorrhoea the symptoms may arise and the disease progress, frequently 
to its end, without any evident local sources of irritation, except that in 
some cases, sources of pericemental debility exist in faults of occlusion, 
leading to overuse, disuse, or misuse of the teeth. 

Mode of Action of the Gouty Poison. — The conditions called gouty 
are held to be due to the retention in the circulating fluids of an excess 
of urates, a waste-product of tissue- and food-metabolism ; this excess 
of material acts as an irritant and inflammation-exciting agent in the 
tissues of the body, producing alterations of function and structure in 
many tissues and organs, but most palpably in the members of the con- 



GOUTY PERICEMENTITIS. 481 

nective-tissue group. The association of an excess of urates with gout 
was demonstrated by Garrod, who detected crystals of urates in the 
serum of blisters from gouty patients. The association became still 
more clear after an examination of the calculi of gout, which were found 
to contain urates. In gouty joint-affections urates of sodium are found 
in the diseased areas. 

Uric acid belongs in the group of animal poisons generated in the 
living tissues of the body, to the general class of leucomal'ns. It is an 
oxidation-product of albuminous matter. There is a series of these sub- 
stances formed in the body, each representing a degree of albuminous 
decomposition by oxidation. The first and least oxidized, is hypoxan- 
thin ; second, xanthin ; third, uric acid ; and, fourth, urea, a substance 
freely soluble in blood-serum, which is excreted by the normal kidneys 
as a product of the nitrogenous waste of the body. That uric acid 
is formed instead of a corresponding amount of urea in conditions of 
faulty oxidation, is the general opinion of pathologists of the present 
day, an opinion not entirely demonstrable, as criticism l will show ; still, 
it furnishes the only tangible explanation of the conditions of its for- 
mation and action at present available. Uric acid exists in the blood- 
serum as a quad-urate of sodium and magnesium. Sodium bi-urate 
is relatively a very insoluble material ; if the sodium be displaced by 
lithium or potassium, the urates of these metals are formed, which have 
a greater degree of solubility. 

If for any reason, notably disease of the kidney, the excretion of the 
urates be interfered with, they accumulate in the circulating fluids, caus- 
ing an excess of urates without an increased production. Its increase 
may, on the other hand, be due to increased formation of uric acid. This 
is observed following upon the ingestion of unusual amounts of nitro- 
genous foods. After the consumption of malt liquors and sweet wines, 
particularly champagne, an increase of uric acid is observed, showing 
that food-metabolism as well as tissue-metabolism is concerned in 
the production of its excess. An increased production is also noted in 
conditions where there is an increased production of leucocytes and a 
diminution of the red corpuscles — the oxygen-carriers — so that the for- 
mation may be clearly traceable to a deficiency of oxygen carried to 
the tissues. 

Another point to be noted is that an accumulation of waste-products, 

even a slowing of the lymph-flow about cells, interferes seriously with 

oxidation, even though oxygen be present in normal amount. The 

existence of these conditions, which cause sluggish vascular flow to 

and from tissues, must, therefore, be regarded as an important factor in 

the presence of an excess of the products of insufficient oxidation. 

1 Levison, Gout, 1896 ; Luff, Croonian Lectures, 1897. 
31 



482 DISEASES OE THE PERICEMENTUM. 

Under some conditions deposits of crystals of urates occur in the 
connective tissues of the body, mainly those in which the circulation 
and the nutritive currents are sluggish, as in articular cartilages, usu- 
ally of small joints ; that is, the deposits occur in parts not freely 
flushed by the movements of intercellular fluids. 

Ebstein believes that local tissue-changes precede and determine the 
point of attack and deposition. His opinion, as originally set forth, 1 
was that coagulation-necrosis of the cells of a part occurred, and the 
tissues acquired an acid reaction, which determined the precipitation of 
urates in the area. 

Van Noorden 2 believes that the point of deposition is determined 
by the local formation of a ferment, and that the deposition is indepen- 
dent of an excess of urates in the circulation. 

A predisposition to degenerative changes exists in the tissues of gouty 
patients, notably in the arteries, leading to atheromatous changes, caus- 
ing increased arterial rigidity. These changes are in part explainable 
by the presence of an excess of the waste-product — urates. Certainly 
in gouty patients, before deposits of urates occur and cause their char- 
acteristic effects, changes in many fibrous tissues are observed which are 
only explainable by constant irritation. Fully developed gout repre- 
sents a degenerative and partially necrotic disease ; but antedating 
these changes, it appears that there is an irritative, perhaps preceded by 
a stimulative stage. 

Increase of connective tissue, as in atheroma of arteries, beneath 
mucous membranes and other situations is found in gouty patients before 
any history of acute outbreaks is noted. 

Such functional disorders as neuralgia, no doubt due to anatomical 
changes, are also observed. All of these point to a long-continued 
period of irritation leading to an increased formation of connective 
tissue. A corollary of this state is a diminished vascularity, followed 
by diminished nutrition, hence debility of the part affected. 

Given, then, a cause of tissue-debility, such as overuse or disuse of 
a part, with an accumulation of the waste-product, urates, the deposi- 
tion of these salts is probable in the ill-nourished and debilitated tissue 
or structure, such as small joints. It will be recalled that the metatarso- 
phalangeal joint, from its anatomical situation, is one of the joints of 
the body subjected to the greatest use ; and lack of normal exercise of 
it (disuse) would be followed by its debility, and determine in a gouty 
patient the deposition of urates in it. These deposits occur first in the 
least vascular part, upon the surfaces of the articular cartilage, and 
excite irritation ; if present in sufficient amount, inflammation of the 
surrounding vascular parts is aroused, and necrosis of the tissues which 

1 Flint's Practice of Medicine, 6th ed. 2 Medical News, Nov., 1895; and Ziegler. 



GOUTY PERICEMENTITIS. 483 

are the seat of the deposit oceurs. This constitutes the condition of 
acute gouty outbreak. Any of the joints may be attacked, although 
usually it is one of the small joints, most frequently the metatarso- 
phalangeal. 

Gout, or uric-acid poisoning, may exist as a chronic affection without 
acute outbreaks ; deposits accumulate in small joints (tophi), as of 
the fingers, causing stiffness and deformity, as the joints are successively 
affected. An injury to a joint may determine the affection in that joint, 
and any joint may be affected (Flint). 

Gout may exist as an obscure affection without any of the joint- 
affections noted. Disorders of the stomach, liver, kidneys, heart, blood- 
vessels, and lungs may all attend chronic gout, and be caused by it. 
The evidence of connection of obscure conditions, such as headache, 
hebetude of mind, lassitude, digestive, circulatory, or respiratory troubles, 
with the gouty condition may only be made manifest by their relief 
through anti-gout therapeusis. 

All forms of gout are largely hereditary. The manifestation of the 
diathesis may skip one generation and appear in the next. Hereditary 
gout in the female may manifest itself as rheumatoid arthritis. In a 
proportion of cases no heredity can be traced, although the existence 
of gout in the individual is unmistakable. 

The deposits in gout are only readily detected when they exist as 
defined concretions. They may be present as fine crystals and escape 
detection. 

Pathology. — The test of the soundness of the theory that there 
are distinctive gouty dental affections depends upon whether their 
causation, pathology, and symptoms are explainable by the phenomena 
of gout exhibited in other parts, and, again, by the effects of anti-gout 
therapeusis. 

First, an examination of the teeth themselves. Teeth lost through the 
disease whose symptoms and clinical history have been given present the 
exterior appearance before described. Upon section enamel, (Jentin, and 
cementum are found to be highly organized. The pulp-chambers are 
frequently almost obliterated, even without external evidences of abra- 
sion or erosion. Data relative to the condition of the pulp and peri- 
cementum are wanting, although from the degree of immobility of the 
teeth, it may be inferred that the pericementum is markedly diminished 
in volume prior to the beginning of the disease. 

A tooth lost through this affection has, as stated, a degree of root- 
denudation — pericemental necrosis — governed by the stage of disease 
at which the tooth was extracted. Calculi found in the necrosed area 
give the reaction of urates, masked by the presence of calcium-phos- 
phate deposits. 



484 DISEASES OF THE PERICEMENTUM. 

Without the existence of any of the local causes of acute perice- 
mentitis, the symptoms of this disease arise ; they may subside, and 
leave the pericementum permanently crippled, or they may cause 
necrosis of more or less tissue and then subside. The same tooth is 
liable to succeeding attacks until the destruction of pericementum is 
complete. 

Local therapeusis alleviates, but does not cure the condition. In its 
earliest stages anti-gout therapeusis affords marked relief. Are these 
phenomena explicable by the pathogenesis of gout ? Acute and chronic 
gout may persist for years in joints of gouty patients, and yet the peri- 
cementum escape ; again, the dental disease may exist and no history 
of gout, hereditary or acquired, be elicited. 

Dental hyperesthesia, a disposition to grind the teeth at night, 
shifting of positions of the teeth, and abrasion have all been noted as 
accompaniments of gout by Graves, Duckworth, Bartholow, Garretson, 
and others. All of these factors admit of explanation upon the theory 
of a gouty causation. 

First, as to the character of the teeth. The high degree of organi- 
zation of the teeth — i. e., the formation of intercellular substance, formed 
matter of dentin — is explained upon the hypothesis of it being similar 
to sclerotic changes in other connective tissues. It is inferred that 
the soft tissues of the pulp and the pericementum are also involved 
in the process which leads to an increase of their fibrous elements. 
Doubtless, also, these changes involve the bloodvessels of these struc- 
tures, lessening their calibre and their elasticity. This would represent 
the primary irritative stage of the uric-acid dyscrasia. Another expres- 
sion of the irritative stage, altered glandular secretion, has been dis- 
cussed under the head of erosion. 

Why should gout attack the teeth (the pericementum) of some 
persons, and not those of others ? and Why should it attack some teeth 
in preference to others ? It must be remembered that the pericementum 
is anatomically a ligament as well as a periosteum, and that the union 
of a tooth with its alveolus is a joint. It is attacked for the same 
reason that any joint may be attacked : because it happens to be a 
weak articulation. The probable explanation of the selective action 
of gout-poison for the metatarso-phalangeal articulation is because this 
joint normally, in walking and standing, does a great deal of w T ork, 
receives a blow and pressure with every step, and therefore w r ould 
suffer early from disuse, according to a general physiological law. If 
it is not vigorously used, and it is not, in many gouty patients, its nutri- 
tion is disturbed and its vascular currents become sluggish. Analogous 
conditions may be established in the dental ligament, the pericementum. 
Owing to an increase in its tenuity and a decrease of its vascular 



GOUTY PERICEMENTITIS. 485 

supply, its nutritive exchanges — its currents — become sluggish. If the 
teeth be used vigorously, the sluggish circulation may be partially coun- 
terbalanced ; if not, vascular sluggishness is increased and a further 
predisposition to degenerations is established. Lack of mastication, a 
common failing in nearly all persons, is very common among gouty 
persons, particularly excessive eaters, who usually take food requiring 
little mastication. It is among this class of persons that gingivitis, 
accompanied by subgingival calculi, is common, producing the first 
variety of pyorrhoea, which may complicate or be aggravated by the 
local action of the gout-poison. The conditions of debility resulting 
from disuse of a structure exhibiting incipient degenerations, need but 
slight exciting causes to give rise to acute disease. The wedging of 
teeth, chance blows, and, among women, thread-biting, may determine 
an injury to the pericementum sufficient to make it the weak joint in 
which the gout-poison settles. In many cases a slight mal-occlusion 
may be the medium of injury to the dental articulation. This is most 
notable in those cases where chronic constructive changes in the peri- 
cementum have caused a thickening of some portion of the alveolar 
process between two teeth, causing the teeth to shift their position, and 
giving rise to the condition termed by Duckworth the " buck teeth" of 
gout. The teeth are brought into mal-occlusion, which determines the 
point of attack — the point of least resistance. These causes, both pre- 
disposing and exciting, may not be in evidence, in which event the teeth 
escape attack. 

Given the predisposing and exciting causes which result in an area 
of lessened resistance in a portion of the pericementum of some tooth, 
when an excess of urates in the circulating fluids occurs, urates are de- 
posited in the area of pericemental irritation ; necrosis of the injured 
tissue, the seat of the deposit, occurs. Whether the deposit precedes 
necrosis, or the necrosis precedes the deposit, as originally set forth by 
Ebstein, is not known : an acid reaction is established which causes pre- 
cipitation of urates. Inflammation is excited in the neighboring por- 
tions of the pericementum, which breaks down, as does also the adjacent 
alveolar process. An outlined or general swelling occurs, which may 
subside, or, if the inflammation persist, a discharge of glairy, mucus- 
like material may occur at the neck of the tooth, or in some cases pus 
— gouty abscess — discharges. The discharge may occur through the 
gum over the site of a circumscribed alveolar loss. As the gum-attach- 
ment is unbroken before the period of discharge, infection of the part has 
presumably occurred in the same manner as it occurs in cases of pulp- 
death without caries. The original uratic deposit afterward becomes ob- 
scured by deposits of the calculi which occur in continued pus-formation. 
These act as continuous irritants, so that the remainder of the pericemen- 



486 DISEASES OF THE PERICEMENTUM. 

turn and alveolar wall degenerates and disappears molecularly. In the 
absence of pus-formation the uratic deposits may be covered in or mixed 
with light phosphatic concretions, as in common tophi. In the ab- 
sence of an apparent exciting cause for the location of the attack, it is 
presumed that the changes in the vessels have proceeded farther in 
some portion of the pericementum of one tooth than in others ; the de- 
bility is most pronounced there in consequence. 

The general pulpal hyperesthesia noted in connection with the earli- 
est stages of the disorder, may be attributed to the presence in the periph- 
eral circulation of irritating material. The same explanation applies 
to the occurrence of attacks of pericemental hyperesthesia, in which 
there is a disposition to grit the teeth. It will be observed that in both 
of these states there is early active hyperemia of the parts. It is pre- 
sumed that this is the antecedent and the cause of sclerotic changes 
which cause increased dentinal formation and increased density of alve- 
olar walls, attended by increased tenuity of the pericementum. 

Prognosis. — The prognosis of the disease depends largely upon the 
form in which it first exhibits itself, and also upon the length of time 
an increased amount of waste-products has been present in the circulation. 
In all grades of the inflammation, except that attended by pus-forma- 
tion, the cure of the general condition is usually followed by a more or 
less prompt subsidence of the dental symptoms, although if a tooth be 
loose, the condition may improve, but does not disappear. If pus form, 
as indicated by the unusual activity of the inflammatory symptoms, 
destruction of tissue, pericemental and alveolar, it will progress until it 
is given vent, no matter how active or effective in other particulars anti- 
gout therapeusis may be. In these cases the tooth is usually lost sooner 
or later. 

One or more teeth may be repeatedly attacked, and if the underlying 
cause be promptly removed, they may partially recover. 

Because one tooth of a denture is affected it does not necessarily fol- 
low that others will become affected ; a single tooth, or two teeth, may 
represent the Aveak articulations or points of selection of the gout- 
poison, and others remaining unaffected. It is usual, however, if the 
gouty condition be not held in abeyance, for successive teeth to become 
affected. 

Treatment. — The treatment is both general and local ; the import- 
ance of general therapeutics outweighing that of local measures of treat- 
ment. 

The local treatment will depend upon the local conditions present. 
Some of these may be similar to those noted in connection with the 
previously described varieties of pyorrhoea — looseness of the teeth, 
mal-occlusion, infection, the presence of dead and foreign material, etc. 



GOUTY PERICEMENTITIS. 



487 



Fig. 377. 




A, calculus. 



Each of these conditions requires correction by means already described. 
As regards the peculiar mode of infection and some of the anatomical 
conditions, the treatment in many respects is similar to that of phage- 
denic pericementitis. The site of actual infection, the situation of 
calculi and of dead tissue, the degenerating alveolar edges, and the 
unbroken gingival margin are similar, except that in the gouty cases the 
gingival attachment may be intact. It is even more important then 
in such cases that entrance to the area of necrosis be made through a 
special opening. A semicircular flap, as described in connection with 
the treatment of phagedenic pericementitis, should 
be raised and the disease-area explored and freely 
scraped to free it from all dead and dying tissue. 
The pockets should be syringed with hydrogen 
dioxid solution and touched with an antiseptic 
stimulant preparation ; any of those previously 
given will answer (Fig. 377). The flap should next 
be stitched into place. An antiseptic mouth-wash 
should then be prescribed. In pyogenic cases find- 
ing vent at the gum-margin the treatment should 
be identical with that of phagedenic pericementitis. 

If the existing constitutional disorder do not receive correction, all 
local measures of treatment will be of but slight avail ; not only may 
the disease appear upon other teeth, but the regenerative processes about 
the teeth which receive local treatment will entirely fail. 

The treatment of the general condition concerns the general prac- 
titioner more than the dentist, but there are frequently attendant cir- 
cumstances in these cases which render it not only advisable but impera- 
tive that the dentist should furnish direction as to diet and prescribe 
medicinally. 

In many cases the evidence of a gouty condition, aside from the 
dental disease — and this is also true of dental erosion — are so faint that 
general practitioners, even if advised of the probable existence of 
masked or obscure gout, refuse to be guided by the indications pointed out 
and the diagnosis made by the dental practitioner. These dental signs 
will, no doubt, in the near future, come to be regarded by the general 
practitioner as valuable diagnostic indications of the existence of 
obscure gout ; the evidences of dental induration, the existence of 
dental erosion, or the occurrence of pericemental degenerations, will all 
be regarded as pointing to the existence of some gouty disorder. 

The general therapeutics of gout embraces medicinal agents and 
regulation of diet, the elimination of the gout-poison and the preven- 
tion of its formation. The principle of general therapeusis applied in 
the treatment of gouty conditions is diuresis. All agents which increase 



488 DISEASES OF THE PERICEMENTUM. 

secretion of urine have a beneficial effect. The ingestion of large 
quantities of water raises the blood-pressure and flushes the tissues of 
the body and the kidneys ; hence elimination of formed waste-products 
is increased. If the water (as many "mineral waters") contains salts 
of potassium, the diuretic effect is increased. Solutions of potassium 
bitartrate (acid tartrate of potassium) are in general use for this purpose, 
forming the basis of many " fever mixtures/' whose object is to rid the 
body of the products of nitrogenous waste. The citrates, tartrates, and 
acetates of potassium, sodium, and lithium, all neutral salts, when taken 
into the circulation are converted in the tissues into alkaline salts — 
carbonates— which render the urine alkaline, if present in sufficient 
amount, and increase excretion, provided they be taken in large 
volumes of water. 

The danger from the presence of urates consists in the excessive 
formation of acid urates, the solubility of which is low. If converted 
into neutral urates, their solubility is increased and the tendency to de- 
position is correspondingly diminished. Upon this fact depends the 
efficacy of salts of lithium in conditions of gout. Taken into the cir- 
culation, neutral lithium urate is formed from the acid urates, an 
increased volume of which can be held in solution by the circulating 
fluids, the tendency to deposition being lessened. If the lithium salt 
be taken with free draughts of water, there is the additional factor 
of free diuresis. E. C. Kirk has introduced the bitartrate of lithium 
as a substitute for the citrate usually employed ; its solvent power is 
greater and it has a specific diuretic action. 

Increase of the alkalinity of the blood and the induction of free 
diuresis are the objects sought. It is by reason of their eliminant 
action that preparations of colchicum act as curative agents in acute 
gouty inflammations. 

Piperazin (C 4 H 1() N 2 , diethylene-diamin) is said to possess twelve 
times the solvent power for uric acid that lithium carbonate has. Hare, 1 
however, failed to obtain any beneficial effects from the use of this drug 
in gout. Stewart 2 has recorded ill cerebral effects from its use. 

The salicylate of sodium is commonly used in gouty affections as a 
uric-acid eliminant, 3 but more particularly to relieve attendant pains. 

As the cases of acute gouty affections are usually readily recognized 
and treated by the general practitioner, the advice of the dental prac- 
titioner applies only in cases without classical symptoms ; his recom- 
mendations, therefore, need scarcely exceed advising the free use of 
water containing potassium or lithium salts. A tablet of lithium 
bitartrate dissolved in a half pint or more of water, to be taken three 
times daily, is usually sufficient medicinal treatment. 

1 Practical Therapeutics. 2 Ibid. 3 Haig. 



GOUTY PERICEMENTITIS. 489 

Advice should always be given as to a dietetic course which will 
minimize the formation of urates and secure elimination of the waste 
formed. 

Measures should be advised to increase the oxidizing function. 
Free exercise in the open air is of first importance, and is only second 
to the correction of anaemic conditions ; this, however, concerns the 
general practitioner, as it involves the prescribing of a course of iron or 
arsenic. Disorders of the intestinal tract and its appendages, par- 
ticularly hepatic disorders, also demand correction. 

The diet should be of a character which will lessen the formation of 
urates. The amount of vegetable food, in proportion to animal, should 
be increased, thus raising the alkalinity of the body-fluids. Red meats, 
and white meats difficult of digestion, increase the formation of urates. 
Poultry and shell-fish in the dietary lessen the formation of urates. 
The consumption of malt liquors notably increases it, and sweet wines, 
particularly champagnes (both sweet and dry), are poisonous to gouty 
patients. Spirituous liquors are also harmful, since they lessen tissue- 
oxidation and produce gastric and hepatic disturbances which cause 
faulty metabolism. 

Recognizing the predisposition which exists in gouty persons to 
active pericemental degenerations, the operator should guard against 
injuries to the pericementum, which might induce a weak articulation and 
precipitate gouty pericementitis. Such teeth should not be wedged ; 
injury to the gum or gum-margins, by the use of improper rubber-dam 
clamps, ligatures driven beneath margins, etc., may excite the first 
stages of a degeneration which will end only in the loss of the abused 
tooth. 



SECTION VI. 



CHAPTEE XXVII. 

DISEASES OF THE DECIDUOUS TEETH AND THEIR TREAT- 
MENT. 

The deciduous teeth are subject to several diseases which affect the 
permanent teeth. Their crowns may be the seat of deposits — rarely, 
however, of salivary calculi. They may be affected by mechanical 
abrasion, dental caries, and acute diseases of the pulp, pericementum, 
and alveolar walls. In deciduous teeth septic pericementitis frequently 
runs a chronic course, but other chronic degenerations of the pericemen- 
tum are rare, except in connection with constitutional diseases, notably 
rachitis. 

Owing to peculiarities of structure and anatomical associations, 
diseases of the temporary teeth present features different from those of 
the same diseases occurring in the teeth of adults. The dentin of 
the deciduous teeth appears never to possess the high degrees of sensi- 
tivity noted in the adult teeth of some persons. In acute affections of 
the pulp the pains have less of a reflex character, being confined to the 
dental region ; nor, so far as subjective phenomena are observed, are 
these pulp-pains of such severity as in adult teeth. The lymphatic con- 
nections of the deciduous teeth appear to be more free than those of the 
permanent teeth, so that involvement of the lymphatic glands — i. e., 
evidence of septic absorption — is more frequently observed in connec- 
tion with diseases of the deciduous than with those of the permanent 
teeth. 

Acute catarrhal inflammations, including several forms of ulcerative 
action, belong so distinctively to the period during which the temporary 
teeth are in position that they are classified as diseases of the mouths of 
children. 

All therapeutic measures, medicinal and mechanical, are directed 
toward insuring the non-septic retention of these teeth for a period of 
but five years, so that they may be and frequently are of a type differ- 
ing from those directed toward the retention of dental organs for a life- 
time ; moreover, they are modified by peculiarities of anatomical rela- 
tionships. 

Loss of the deciduous teeth through other than physiological pro- 

491 



492 DISEASES OF THE DECIDUOUS TEETH. 

cesses should not be regarded with unconcern, for while it is true that 
pyogenic processes may exist for a long period upon the roots of a tem- 
porary tooth, its permanent successor underlying it being, at least so 
far as outward form is concerned, unaffected, it is more than probable 
that it is aifected in its deeper histological structure and anatomical 
organization. The effects of too long retention and too early extraction 
of the deciduous teeth have been already discussed under the head of 
malpositions of the teeth. 

Deposits upon the Teeth. 

The deposits upon the deciduous teeth are usually confined to the 
cervical portion of the labial and buccal enamel, appearing as crescentic 
lines of green stain. These deposits, together with white deposits of 
debris in the gingivo-dental depression, are most frequently observed 
in the mouths of children whose teeth receive little or no care. They 
are probably due to the growth of chromogenic fungi in the remains 
of the enamel-cuticle, which persists longer in this situation than in any 
other. The only clinical significance, or rather pathological significance, 
of these deposits, is that they appear to furnish a predisposition to dif- 
fuse and ulcerative stomatitis ; the connection between the two is by no 
means clear, although the association is frequent. 

Such deposits are to be removed as described in Chapter XXIV. This 
trifling operation, as well as those of greater extent upon the deciduous 
teeth, is attended by difficulties absent in operations upon the teeth of 
adults. Children may be presented for dental treatment as early as 
the third or fourth year. At this age they are too young to appreciate 
the importance of dental service, or to be reasoned with ; difficulties 
which are still further increased by insubordination, frequently abetted 
rather than curbed by the child's guardian. Children will rarely submit 
to inconvenience, much less to any degree of suffering incidental to den- 
tal operations. The physical character of the infantile mouth furnishes 
additional obstructions : the entrance to the mouth is small ; the mouth- 
cavity is shallow owing to the shortness of the teeth and the alveolar 
process ; and the salivary secretion is very free ; thus dryness of the 
parts, one of the most efficient aids to accurate and painless dental ope- 
rations, is but imperfectly attainable. It is rare that the rubber-dam 
can be used before the sixth or seventh year. The muscles of the tongue 
and lips of children are singularly uncontrollable. 

Much may be accomplished with children through tact upon the part 
of the operator. Until the child has become familiarized with the 
dental chair, and with having its mouth examined, teeth touched, 
pressed upon, etc., operations should be confined to trifling procedures 
occupying but few minutes at most. The growing familiarity will 



ABRASION OF THE DECIDUOUS TEETH. 493 

secure quiet of the patient, the most essential preliminary to operating. 
Lack of patience, or the use of force upon the part of the operator, 
is, except in rare cases, an effectual bar to present or any future opera- 
tions. Many children may be given a permanent dread of dentists and 
dental operations by some ill-considered move upon the part of the 
operator. 

Even premising quiet of the patient, the form of the mouth, lack 
of dryness, and necessity for short sittings make operations on the 
deciduous teeth a compromise between what should be done and what 
can be done. 

It is quite as important that the temporary masticating apparatus 
should be kept in full working condition as it is for the permanent. As 
emphasized by Guilford, 1 during the period that the deciduous teeth are 
in position the alimentary canal and its glandular appendages are still in a 
developmental stage, and any disturbance of oral physiology, resulting in 
the stomach receiving poorly masticated food- stuffs, may react upon its 
normal development. Such cases may at least induce functional gastro- 
intestinal disturbances of some gravity. The existence of painful dis- 
eases of the teeth materially hinders mastication, so that their correction 
is demanded to relieve pain and to restore the partially lost function. 

Abrasion of the Deciduous Teeth. 

The occlusal surfaces of the deciduous teeth may wear away to a great 
extent. In some cases, this appears to be due to active fermentative 
changes in the mouth, which cause a general acid reaction of the fluid 
contents of the mouth ; owing to faulty organization of the cusp-enamel, 
it may be readily soluble, and the teeth may be worn down and abraded 
through the combined action of solvents and the mechanical abrasion 
of mastication. 

The cases of this condition observed, while associated with the 
presence of dental caries in some of the teeth, showed an exemption 
from caries in the teeth most abraded — those which were washed clean. 
More than this, in some of the teeth, worn nearly to the gum-margin, 
evidences of secondary constructive action upon the part of the pulp 
appeared ; the teeth were worn beyond the original limits of the pulp- 
chamber and the pulps were still vital. 

Another form of abrasion may be seen in teeth whose tissue-organ- 
ization is not faulty. Children whose rectums are infested with 
parasites, as the ascaris lumbricoides, taenia (tapeworm), etc., and who 
suffer from irritable bladder due to hyperacidity of the urine, com- 
monly have a reflex stimulation of the muscles of mastication during 

1 Proc. Academy of Stomatology, 1896. 



494 DISEASES OF THE DECIDUOUS TEETH. 

sleep, which causes the forcible grinding of the teeth. The enamel 
of the teeth may be worn down and abraded, as observed in adults. 

Treatment. — The treatment of abraded surfaces where the dentin is 
exposed is to wash the mouth with an antiseptic, not one containing 
chlorids, but hydrogen dioxid. Dry the dentin-surfaces and rub them 
vigorously with fused silver nitrate. This silver salt, rubbed upon dentin, 
forms with its organic constituents an albuminate of silver, which is 
persistently antiseptic. Under the influence of light it is reduced to the 
oxid of silver, which is slowly converted into silver lactate through the 
lactic acid produced in the mouth. Silver lactate, as contemporary 
surgical practice testifies, is a most efficient antiseptic. Contrary to 
previously held opinions, Truman's experiments l indicate that silver 
nitrate is a very penetrating coagulant, so that the reactions above given 
persist for a long period. It is in consequence of these peculiarities 
that silver nitrate is found so effective in checking and preventing 
dental caries. 

The continued use of antiseptic mouth-washes is advised. Listerine, 
to which a minute portion of saccharin has been added to sweeten it, 
diluted one-half, is an agreeable antiseptic for continued use. 

In cases of grinding of the teeth, the source of the reflex disturbance 
should be removed by the general practitioner. Belladonna, which chil- 
dren stand well relatively large doses of, is the medicinal agent most 
used to lessen vesical irritability. The urine, however, must have its 
acidity lessened through an increased vegetable diet, and, if required, 
potassium salts. Rectal parasites should be removed through the use 
of vermifuges — santonin, male fern, or others, depending upon which 
parasite is present. Small seat-worms, causing pruritus, may be 
destroyed by rectal injections of weak solutions of phenol sodique, 
a teaspoonful in a half pint of water. 

Caries of the Deciduous Teeth. 

Unless constant supervision of the deciduous teeth be exercised, 
caries is very liable to progress to the extent of pulp-exposure without 
the previous warning sign — dentinal sensitivity. 

While the canal-portions of the pulps of these teeth are frequently 
fine, flattened, and tortuous, the pulp-chamber has a relatively large size, 
so that pulp-exposure follows quickly upon loss of a section of enamel. 
Eternal vigilance is the price of pulp-salvation in the deciduous teeth. 

The approximal surfaces of the deciduous teeth appear to be more 
quickly and generally affected than the occlusal surfaces. Again, the 
occlusal surfaces of the second molars are more frequently affected than 
those of the first molars. The anatomical forms and arrangement of 

1 Proc. Academy of Stomatology, 1895. 



CARIES OF THE DECIDUOUS TEETH. 495 

the teeth explain these conditions ; the approximal surfaces particularly 
of the molars, and the occlusal surfaces of the second molars, afford 
lodgement for food-debris more readily than do other situations. 

It is rare that decided pain, increased by applications of cold or 
heat, and excited by the presence of sugar in the mouth, occurs before 
actual exposure of the pulp. In a majority of the cases which present 
themselves throbbing pain, indicative of pulpitis, is present. 

If cavities are observed before pain has been complained of, and 
prompt and quickly subsiding response to applications of cold water 
is obtained, indicating a normal pulp, the cavity should be excavated, 
with more regard to removing the marginal caries than to thorough ex- 
cavation, and an application of hydrogen dioxid made. The dentin is 
dried, and an application of a 20 per cent, solution of silver nitrate is 
made for a few minutes, the cavity being subsequently filled. 

In cases of adjoining approximal cavities there is a disposition for the 
affected teeth to press together and lessen the size of the dental arch. 
Bonwill advises as a practice, followed by uniformly good results in 
such cases, to cleanse the cavities (Fig. 378) and insert masses of pink 
gutta-percha base-plate. The constant biting upon the 
gutta-percha causes a separation of the teeth which in- FlG - ^ 78 - 
creases the size of the arch and affords additional space i%^\ 
for permanent successors. He advises that before the Y*3w*f 

gutta-percha masses are inserted that small pieces of ^fiS^ 

blotting-paper saturated with carbolic acid be laid |^p^\ 

against the dentinal walls and the gutta-percha be \^^ 

packed over them. The more efficient and persistent Mode of P re P arm s 

. . . . approximal cav- 

antiseptic silver nitrate may be applied instead of the ities. 
carbolic acid. Kirk advises that asbestos-felt be heated 
to destroy any organic matter present in it which might combine with 
the silver, and then be soaked in a saturated solution of silver nitrate, 
dried, and kept in dark bottles away from the light. Small pieces of 
the prepared felt may be used as described. 

The silver-nitrate method is particularly applicable to shallow cavi- 
ties in which excavation for filling is impracticable. The dentin-surface 
is cleansed and dried, and the fused silver nitrate is rubbed upon the 
surface. This may be done after the method of Craven : a platinum 
wire is dipped into the powdered salt and held over a flame until the 
powder fuses into a button. By this means applications can be directly 
and accurately made. 

These shallow cavities frequently form upon the distal walls of 
second molars, and the erupting permanent first molar crowds into the 
carious area, not only reducing the space for the future bicuspids, but 
inducing caries in the mesial wall of the permanent tooth, and permit- 



496 DISEASES OF THE DECIDUOUS TEETH. 

ting the deep invasion of, and pulp-destruction in the temporary tooth. 
If these cavities can be given a retentive form/ it should be done, and 
a filling having an exaggerated and rounded contour inserted, against 
which the erupting permanent tooth will press with a minimum of con- 
tact-area. In case of non-retentive form a disk is used to cut away the 
surface, leaving above the neck of the tooth a shoulder-like projection 
to hold back the permanent tooth (Fig. 379). The cut surface should 
be treated with silver nitrate. 

Diseases of the Pulp. 

If the case be seen at a stage when paroxysmal pain is caused by 

applications of cold, indicating active hyperemia of the pulp, an attempt 

should by all means be made to soothe, protect, and maintain the vitality 

F 379 of the pulp. The principal object in maintain- 

f^T^H /^fe^-s^ * n £ vitality of the pulp is that the physiological 

^ _ W{ ^ 1 process of root-resorption may not be aborted, 

ll /\ [f\\ -\\ prevented, or deranged. It is undoubtedly 

// //' \ \\ \\..---.\\.-v;:VN true that root-resorption does occur in the ab- 

lyf''' ^%o} V._J\— -''' sence of a pulp, if the roots be in an aseptic 

f \ /) condition ; 2 but in the absence of the pulp the 

^>-::::;>' process is irregular and incomplete (Fig. 380), 

1 ZZTpon t°he STan and mav no1 ; occur - A g ain > [t is probable that 
of the temporary second mo- the destruction of the pulp and the resulting 

imperfect resorption may disturb the nutritive 

balance in the developing alveolar structures in a manner at present 

unknown. The obtundent oils are of essential service in all of the 

pulp-disturbances of children. The oils of cloves and gaultheria are 

well-known domestic remedies for the toothache of children ; thymol 

is the most effective. The cavity of decay is syringed with tepid 

water and dried, and a pellet of cotton dipped in one of these oils is 

inserted. The cavity is given a retentive form, its walls painted with 

a non-conducting varnish, or, what is better, a pulp-cap filled with a 

paste (thymol, glycerin, and zinc oxid) is laid upon the deep wall of the 

cavity and a filling of zinc phosphate flowed over it. 

If evidences of active pulpitis — repeated paroxysms of pain, par- 
ticularly throbbing pain — occur, it is advisable to destroy and remove 
the pulp. If soothed, and the cavity filled, the pulp dies and decom- 
poses, and septic pericementitis arises. In any event, the pulp is 
first reduced to a condition of quiet. 

As to the means of destroying the pulp, it should be remembered that 
pulp-exposure, although it may occur at a very early age, usually occurs 

1 Woodward, Proc. Academy of Stomatology, 1896. 

2 Proc. Academy of Stomatology, 1896. 




DISEASES OF THE PULP. 497 

where the process of root-resorption has made some degree of advance ; 

hence the communication between the pulp and apical tissues is more free 

than when the constriction of the apical 

foramen existed. It is evident, therefore, Fig. 380. 

that the devitalizing agent (arsenic) must be 

used with extreme care, and in minimum 

amount, to prevent its passage into the 

apical circulation. The usual concomitant 

x A B 

of the specific necrotic effects of arsenic upon A% root-resorption of puipiess 
adult pulps— insulation of the pulp-circula- t00th: B > normal resorption; 

1 r . J fe L L vital pulp. 

tion at the apical foramen — will probably not 

be in evidence because of the increased size of the foramen. 

The usual shapes of cavities leading to pulp-exposure in temporary 
teeth demand that extra precautions be taken to prevent the escape 
of arsenic from the cavity upon the gum ; moreover, that most useful 
adjunct, the rubber-dam, may not be applicable, so that the dryness of 
the cavity is imperfect. For these reasons the arsenic should be con- 
tained in devitalizing fibre. The amount used should be very minute 
and well diluted. The fibre is laid upon the exposure and retained by 
means of cotton and sandarac, or temporary stopping. If the evidences 
of acute pulp-disturbance have been very severe, it is advisable to retain 
the fibre by flowing over it thin zinc phosphate to avoid pressure. The 
application is not to remain more than twenty-four hours, and, if root- 
resorption have progressed, for not more than twelve hours. After this 
time the pulp-chamber is to be opened, when it may be found that the 
pulp has still a slight degree of sensitivity. Goddard L advises that gly- 
cerole of tannin be then sealed in the cavity for a week to tan the pulp. 

Other means have been suggested and employed to effect pulp- 
destruction, to avoid the dangers incident to the use of arsenic. Darby 
uses with success a paste of about ^ gr. of cantharides in carbolic acid. 
Dunbar 2 states that aqua ammonia? applied to a pulp will effect its 
destruction. Tr. iodin has been advised by others. Increasing press- 
ure by cotton pellets charged with oil of cloves is a slow method of 
destroying a pulp. 3 

The pulp is removed as from the adult teeth, any living filaments 
being destroyed by a drop of trichloracetic acid. Previous to opening 
the canals the mouth should be drenched with antiseptics, and the 
carious cavity be repeatedly washed with pyrozone. Dryness should 
be maintained as well as possible, and the rubber-dam used where- 
ever it can be applied. The cleansed canals are filled with an 
antiseptic oil, dried, and filled at once. Two materials offer themselves 

1 American Text-book of Operative Dentistry. 

2 Quoted by Goddard, Ibid, 3 Flagg. 

32 



498 DISEASES OF THE DECIDUOUS TEETH. 

for this purpose in preference to all others — melted paraffin and balsamo 
del deserto. The paraffin may be combined with one of the iodin 
preparations, iodoform, aristol, or nosophen. 

Septic Pericementitis. 

Septic pericementitis presents itself as an acute or a chronic condi- 
tion following upon death and putrescence of the pulp. It may arise 
in open cavities, or under fillings which were placed over dying 
pulps. 

Its symptoms are those of septic apical pericementitis : the swelling 
is pronounced ; pain is not so severe as in adult teeth, the tooth be- 
comes very loose, and the duration of the disease is shorter than in the 

adult. The general symptoms, however, are fre- 
quently much more pronounced than in the adult ; 
the inflammation may be attended by a chill, and 
frequently by a pronounced fever ; the neighbor- 
ing lymphatic glands may in a few hours exhibit 
evidence of the presence of septic matter in them, 
by swelling and tenderness. The point of exit 
of the pus is usually directly over the affected root, 
and not very far from the gum-margin (Fig. 381). 
Showing the~reiations of If pus-exit be delayed, there is frequently a dispo- 
an abscess upon a tem- s ition to a stripping of the outer alveolar perios- 

porary tooth with the ... . . ,. 

crown of a developing teum. This, in connection with wide spreading of 
permanent tooth under- t ^ i n fl amma tion, is marked and common in stru- 

lymg it. ^ ' 

mous children. 

Treatment. — The treatment consists in immediate evacuation of the 
pus and washing out the infected tract with antiseptics. The patient's 
head is steadied with the left hand, which also prevents the child seeing 
the bistoury. The last fingers are rested upon the teeth to prevent slip- 
ping of the knife through movement of the head of the child, and a 
direct cut is made to the process. The nozzle of a syringe charged with 
pyrozone is passed into the tooth-cavity and the fluid is driven through 
the abscess-tract. This is to be repeated until bubbling ceases. The 
cavity of decay is sealed after placing in it a pellet of cotton saturated 
with 2 per cent, formalin solution or similar disinfectant. 

As soon as acute symptoms have subsided, an examination of the 
canals should be made to determine the amount of root-resorption. If this 
have progressed far, it will preclude the use of the more powerful germ- 
icides used in canal -cleansing. In any event, strong sodium dioxid can be 
used in the pulp-chamber, but its introduction into the canals must be 
guarded. Sterilization is effected there, by repeated washings with 
hydrogen dioxid or meditrina, followed by drying the canals and filling 




SEPTIC PERICEMENTITIS. 499 

them with cotton and an antiseptic oil — thyme or cassia — to test the 
thoroughness of disinfection. If the fistula heal and the tooth be- 
comes tight, and the cotton when removed from the root has no odor 
of putrefaction, the canals should be filled with paraffin and aristol, or 
balsamo del deserto. In cases of high fever, where immediate access 
cannot be gained to the root-canals for disinfection, the immediate 
extraction of the tooth may be necessary. 

The treatment of chronic abscess is similar to that of the acute 
variety after active inflammation has subsided. A longer time, how- 
ever, is required for sterilization, as the dentin of the root is usually 
badly contaminated by noxious material and the soft tissues are in a 
state of debility, a condition identical with chronic infective ulcer. 
Sodium dioxid may be used with comparative freedom in these cases, as 
the passage of a small amount of the solution acts as a caustic to the 
diseased tissues beneath. Campho-phenique may be pumped into the 
canals of such cases without fear of ill-results. 

If inflammatory symptoms run high, particularly in debilitated 
children, before root-resorption has progressed to any considerable 
extent, limited alveolar necrosis may occur, and a sequestrum be 
formed, which will require removal. In such cases, however, the 
tooth need not be extracted, if the sepsis can be controlled and the 
tooth be not markedly loose. 



CHAPTER XXVIII. 
REFLEX DISORDERS OF DENTAL ORIGIN. 

Recognizing pain as a condition produced through the overexcita- 
tion of sensory nerves, a reflex pain may be defined as a pain referred to 
some point other than that of its origin. Pain referred to the distribu- 
tion of a sensory nerve may be due to overexcitation of any portion of 
the nerve ; in its terminal distribution ; to diseases affecting any portion 
of the nerve-trunk, or to disorders affecting the central termination of 
the nerve. Again, irritation of one sensory nerve may be referred to 
some other sensory nerve. The condition is called neuralgia. 

As both the upper and the lower teeth and their surroundings 
receive their neural supply from branches of the fifth pair of cranial 
nerves, discussion of this subject is confined to causes operating within 
the distribution of that nerve. 

As such general conditions as malaria, syphilis, and forms of ansemia, 
operate to produce neuralgia which may be referred to the teeth, or the 
parts about them, only those cases will be regarded as dental which 
have undoubtedly a dental origin, as evidenced by disappearance of 
the neuralgia following cure of the exciting dental condition. It should 
be noted, however, that vague and sometimes severe pains referred 
to the teeth may entirely disappear after the cure of some constitu- 
tional disorder. For example, cases of periodically recurring dental 
pain have been entirely relieved through the administration of quinin 
and arsenic; the pains were clearly of malarial origin. Pain about the 
teeth in syphilitics has disappeared after the administration of iodids. 
Pain referred to the teeth in anaemic patients has disappeared after a 
long course of chalybeates. 

Reflexes of dental origin are both motor and sensory, the latter far 
outweighing the former in importance. Motor reflexes may be noted in 
the quick spurt of saliva from the ducts of the salivary glands upon 
infliction of pain in the teeth, and by the spasmodic contraction of the 
muscles about the mouth when the pulp of a tooth is deliberately irri- 
tated. Twitching of the muscles about the face is a common accom- 
paniment of trigeminal neuralgia. 

Before direct association of dental diseases with pains in other parts 
can be clearly demonstrated a review of those conditions of the teeth 
attended by pain must be made. 

500 




Fig. 382.— Plan of the fifth cranial nerve, showing the relationships of the dental nerves. 

(After Flower.) 



502 REFLEX DISORDERS OF DENTAL ORIGIN. 

Dental pain arises in consequence of disorder of the sensory struct- 
ures ; these are situated in the pulp, and by continuation throughout 
the dentin ; and in the pericementum. The roots of teeth may have 
unusual anatomical relations with other sensory structures than their 
own pericementum. Dental pains, therefore, may be discussed, first, in 
connection with affections of the dentin and pulp, and, secondly, with 
those of the pericementum. 

It was stated, in discussing the diseases of the dental pulp, that this 
organ is not the seat of the tactile sense, and that, like other organs 
having a kindred physiological relationship, irritation excited in it is 
not located, but is referred to some other part. While all reflex dental 
disturbances are, as a rule, located in some part of the great nerve- 
branch supplying the source of irritation, the irritation may be reflected 
to distant parts : first, of the same cranial nerve, and, secondly, to other 
nerves. That is, pain having its origin in one of the upper teeth is 
most likely to be referred to a point or points in the distribution of the 
superior maxillary nerve. Disturbances in or about the lower teeth are 
usually referred to the distribution of the inferior maxillary nerve. In 
affections of either upper or lower teeth the pain may be referred to the 
first division of the fifth nerve. In all of these cases, but most notably 
in connection with disturbances of the upper teeth, the usual symptom 
of trifacial neuralgia — tenderness of the supra- and infra-orbital nerves 
at their points of emergence upon the face, the supra- and infra-orbital 
foramina — is commonly present. 

Cases are extremely rare where the reflex pain is referred to the 
opposite side ; indeed, so unusual is this occurrence that its mention 
warrants suspicion that other sources of irritation exist upon the side 
referred to. 

The extent or acuteness of reflex pain bears no direct relation to the 
apparent extent of the source of irritation. 

As might be surmised from the function of the dental pulp, painful 
reflex dental disorders are more common in connection with diseases of 
the pulp than with those of the pericementum. 

Reflex Neuralgia from Exposed Dentin. 

The exposure of the dentin to external sources of irritation is fol- 
lowed by reactions governed, first, by the degree of sensitivity inherent 
in the protoplasm of the tissue; and, secondly, by the degree of 
hypersensitivity induced in it. Reflex disturbance due to these irri- 
tations is more common in the class of women called " neuralgics " than 
in other persons. Like direct pulp-pains, unless actual pressure be 
exerted upon the affected tissue, there is no localized pain. In the 
absence of deliberate irritation, the pain may be referred to any portion 



REFLEX NEURALGIAS FROM PULP-DISEASES. 



503 





Sites of dentin exposure frequently associated 
with reflex pains. 



of the peripheral distribution of the fifth nerve upon the face ; but if 
an acid liquid, such as lemon-juice or vinegar; or sugars, be taken into 
the mouth, pain is excited, which is referred indefinitely to the teeth of 
one side, frequently of one jaw. Reflex pains due to this cause are 
much more likely to appear when there is but little loss of dentin. 

When carious cavities have proceeded to any depth evidences of 
direct pulp-disturbance are obtained through the increased response to 
thermal changes. 

Reflex pains from exposed dentin appear most common in connection 
with exposures at the neck of the tooth and upon abraded areas. 
Obstinate and persistent neural- 
gia, positively referred to another 
nerve-branch, may apparently owe 
its origin to so slight a cause as ex- 
posure at the neck of a tooth (Fig. 
383) of a line of dentin. The proof 
of the connection between the two 
is made clear by a disappearance 
of the neuralgia after the exposed 
dentin has been subjected to the action of powerful caustics, destroy- 
ing the dentinal filaments to some depth. The connection between the 
two may be revealed only by accident ; the contact of a tooth-pick, a 
dental instrument, or the finger-nail may induce a paroxysm of pain. 

While in some cases the dental origin of reflex pain may be made 
clear by the induction of a painful response in the area of reflection, 
by irritating a tooth-pulp, this reaction is not constant. The causal 
relation is only certain when the cure of localized dental disease is fol- 
lowed by a disappearance of the neuralgia without further treatment. 
This proof should be exacted in all cases. 

The most common sources of neuralgic attacks about the face are 
diseases of the eyes and teeth. In general terms, diseases of the 
eye give rise to reflex pains referred to the distribution of the first 
branch of the fifth nerve ; diseases of the teeth usually cause reflex 
pains in either the superior or inferior maxillary divisions, according as 
the upper or lower teeth are affected. In all painful affections of these 
nerves attention should at once be directed to the organs named. 

Reflex Neuralgias from Pulp-diseases. 

The disturbances require classification according to the distance 
between their source and their manifestations. 

In the Fifth Pair of Nerves. — Pain referred to a different spot 
or area than its origin is a characteristic of all pulp-diseases. The 
extent of its reflection depends, first, upon the patient, as noted in con- 



504 



REFLEX DISORDERS OF DENTAL ORIGIN. 



Fig. 384. 



nection with the reflex pains from exposed dentin ; and, secondly, upon 
the variety of pulp-disease. In neuralgic patients any variety of pulp- 
disease may cause comparatively distant pains. But, as Black has 
pointed out, 1 the general rule is, that the more chronic and profound 
degenerative diseases of the pulp are much more liable to give rise to 
distant reflex pains than are acute pulp-diseases. 

The pains of acute hyperemia and of acute inflammation of the 
pulp are usually referred to the region of the tooth aifected, or to a 
corresponding nerve-trunk. In conditions of venous hyperemia, nodu- 
lar calcification, chronic inflammation, and, later pulp-degenerations, 
the pains may be of such character that their dental origin is only 
determined after persistent search. Particularly is this true of the 
growth of pulp-nodules. The source of the reflex pains is all the more 
obscure from the fact that in these chronic degenerations direct dental 
symptoms may be entirely absent, and are only elicited upon the most 
searching examination and exhaustive tests. 

There is no constancy in the location of the pain due to any of 
these causes ; but tenderness of the eyeball upon pressure ; persistent 
pain in the temporal and anterior auricular regions, particularly in con- 
nection with pulp-diseases of the lower posterior teeth ; in the ear itself, 

a common site of the reflex pain excited 
by chronic pulp-inflammation and sup- 
puration of that organ ; behind the ear, 
back of the lower border of the mastoid 
processes, tender spots may develop ; ten- 
derness to pressure may appear at the 
supra- and infra-orbital or mental fora- 
men, and about the chin. In the same 
class of diseases the pains may frequently 
radiate as far as the shoulder. Many of 
these cases receive attention from the gen- 
eral practitioner, and the painful attacks 
recurring at irregular intervals are re- 
lieved by analgesic remedies — phenacetin, acetanilid, exalgin, etc. — and 
no attention paid to a probable dental source of the disorder. It should 
be a routine practice to examine the teeth in cases presenting pains of 
the type and in the situations described. Immediate search should be 
made for teeth containing pulps in late degenerative stages (see Symp- 
toms of Disease of the Pulp). Acute diseases of the pulp, including 
suppuration and, notably, abscess of the pulp, usually have attention 
directed to the teeth through pain induced by thermal changes, so that 
their diagnosis is quickly made. Not so, however, with the chronic 

1 American System of Dentistry, vol. i. 




Spots of tenderness in reflex neural 
gias of dental origin. 



REFLEX PAINS FROM DISEASES OF THE PERICEMENTUM. 505 

degenerative changes, except possibly of pulp-nodules ; for if the pulp 
is in the late stages of degeneration, it may require repeated applications 
of cold and heat to elicit a response from teeth which do not respond by 
tenderness upon percussion. 

Failing to obtain evidence of pulp-disorders, examination should 
be made for exposed and hypersensitive dentin. Then, examination 
of the pericemental reaction of each tooth should be made and for any 
evidences about the teeth pointing to pericemental disturbance (see 
later). 

Lauder Brunton l records that, in his own case, temporal neuralgia 
accompanied by tender eyeball was found due to exposed dentin upon 
the posterior cervical surface of a lower third molar (Fig. 383). The same 
writer 2 announces " that so frequently are headaches dependent upon de- 
cayed teeth that in all cases of headache the first thing I do is to care- 
fully examine the teeth •" as should everyone else. Brunton explains 
the painful reaction upon the accepted hypothesis of the pathology of 
megrim, that it is due to spasmodic contraction of the peripheral end 
of an artery, with dilatation of the proximal portion. " Irritation in 
the tooth is reflected to the cervical sympathetic ganglia and causes 
spasmodic contraction of the arteries through irregular stimulation of 
the vasomotor nerves." 

Reflex Pains from Diseases of the Pericementum. 

As a general rule, pericemental pains are located at the affected 
tooth ; but in some of the disorders, particularly those in which 
either hyperemia or inflammation, acute or chronic, is not present, the 
teeth may not be tender upon percussion, and yet excite reflex pains 
in other parts, the proof of the connection being determined by a dis- 
appearance of the pain upon extraction of the tooth. The roots in 
such cases usually present either a hypertrophy of cementum, or show 
that resorption of a portion — it may be a major portion — of the root 
has occurred. 

In cases of hypercementosis it is assumed that the source of the irri- 
tation is pressure upon the nerves of the pericementum by the hyper- 
trophic growth. Very widespread disorders may arise from this source 
(see cases of insanity, etc.). 

Flagg records 3 many varieties of trifacial neuralgia ; pains in remote 
parts of the body ; grave functional disorders of the eye and ear ; and 
motor disturbances — chorea, epilepsy, and paralysis — having a direct 
demonstrable connection with hypercementosis. He mentions violent 

1 St. Bartholomew's Hospital Reports, vol. xix. Reprinted in hi* Disorders of Digestion. 

2 Ibid. * Denial Cosmos, 1S78. 



506 REFLEX DISORDERS OF DENTAL ORIGIN OF PERICEMENTUM. 

attacks of trifacial neuralgia as the most common reflex disturbance 
from this source ; and next, long-continued pains in the ear or eye of 
the affected side. The existence of acute disease of these organs is 
usually diagnosed by the general practitioner. He states that oral 
and ocular disturbances, both functional and painful, are of gradually 
increasing severity. 

In examining for a dental source of such pains, exposed dentin, pulp- 
diseases, and inflammatory affections of the pericementum should be first 
excluded. In examinations by percussion a different response may be 
obtained from some one tooth than from the others. Hypercementosis 
of a particular tooth is indicated by finding the gum-line slightly re- 
ceded, and the tooth-attachment unusually firm ; if, in addition, vague, 
heavy dental pains have persisted at intervals over a long period, the 
diagnosis is probable. It is only certain when tapping upon the tooth 
brings on a paroxysm of neuralgia, or where a skiagraphic view actually 
exhibits the hypertrophic growth. The remedy is extraction. Any 
root-fragment left unextracted may perpetuate the reflex disorder. 

Painful affections referred to the neighboring region of the affected 
tooth, or diffused through the distribution of the corresponding nerve- 
trunk, or to the eye or ear, may accompany the process of resorption 
of the roots of permanent teeth. Gillman l records a case where facial 
paralysis disappeared upon extraction of a tooth which had long been 
the seat of disturbances, and which upon extraction revealed resorption 
of its root. 

Ail of the acute or chronic, septic or non-septic inflammations of the 
pericementum, may give rise to reflex pains. In many of these cases 
the cause of the reflex irritation is due, perhaps, to sepsis, rather than 
to a pure neurotic connection. The most common causes of the reflex 
pains are found in that stage of pericemental irritation which antedates 
acute septic apical pericementitis, and which accompanies the chronic 
inflammations of the apical pericementum from any cause. In some 
of these cases reflex neuralgia may play a subordinate part to general 
infection from the focus of disease. The reflex nervous disorders con- 
sist in painful disturbances in the distribution of the fifth nerve and dis- 
orders of special senses, particularly that of hearing. Unless an exacer- 
bation of the reflex disorder, or symptoms referable to that region, be 
induced by pressure or percussion on the tooth, a causal relationship is 
only made out by either relieving an existing dental disorder or extract- 
ing the teeth. The symptoms of septic intoxication and septicaemia must 
be carefully differentiated from reflex neuralgias in such cases : the latter 
are rare ; the former probably more frequent than supposed in connec- 
tion with septic dental diseases. 

1 Boston Med. and Surg. Journal, 1867. 



PAIN REFERRED TO NERVOUS TRACTS OTHER THAN FIFTH 507 

Impacted Teeth as a Cause of Neuralgia. 

Neuralgia of varying degrees of severity is a common accompaniment 
of impacted teeth. It is most frequently noted in connection with erup- 
tion of the lower third molars, not only because this tooth is the one 
most frequently impacted, but because of the anatomical relations of its 
roots with the inferior dental nerve. 

In the milder forms of impaction, those in which eruption, though 
delayed, is subsequently completed, the pains are commonly localized 
and associated with but occasional attacks of rigidity of the masseter 
muscles. If, however, the crown present horizontally or nearly so, and 
its progress is arrested by impaction against the posterior wall of the 
lower molar, or if its progress be arrested by permanent imprisonment 
of the advancing crown between the posterior surface of the second 
molar and the base of the coronoid process, not only may intense local 
pains be induced, but severe reflex disturbances of both a sensory and 
motor character may occur. In some of these cases root-formation is 
completed, although the crown of the tooth does not advance, in which 
case compression of the inferior dental canal and its contents may occur 
and cause grave reflex disturbances. The local irritation about the root, 
due to root-growth, may excite continued constructive action by the 
pericementum, and the hypertrophic growth in its turn may be the 
source of reflex neuralgias. 

Complete imprisonment of the entire tooth has been found to be the 
exciting cause of facial neuralgias, for the cure of which extensive sur- 
gical operations have been performed. 

Impacted cuspids and other teeth may excite no other symptoms than 
reflex neuralgia. The possible connection between an impacted tooth 
and neuralgia is made out after excluding other dental causes, when it 
may be observed that one or more of the permanent teeth are absent 
from the dental arch, at dates long after their normal time of eruption. 

A condition equivalent to partial impaction, in which dental irrita- 
tion may be the source of reflex neuralgia, is seen when the teeth are 
crowded — jammed into arches too small for their accommodation. Dur- 
ing the period of eruption severe maxillary pains may recur at intervals. 

Pain referred to Nervous Tracts other than the Fifth. 

The most common disturbance appearing in other cerebro-spinai 
nerves than the fifth, due to dental diseases, is an affection of the eighth, 
or auditory nerve. Cases of deafness have been recorded due to dis- 
eases of both pulp and pericementum, notably to hypercementosis. 
Deafness which has persisted for a long period has been markedly 
lessened by the extraction of teeth the seat of disease. Cases of sup- 



508 REFLEX DISORDERS OF DENTAL ORIGIN. 

purative otitis media have been regarded as having pathological associa- 
tion with septic diseases about the teeth from the fact that the aural 
trouble subsided immediately after extraction of the diseased teeth. 

Sensory disturbances of the eye, associated with dental diseases, have 
been alluded to ; in addition to these, grave structural and functional 
diseases of the eye, traceable to dental causes, have been recorded, such 
as motor, sensory, and special sense-disturbances, together with trophic 
disorders. 1 Among the latter may be mentioned corneal inflammation 
and ulceration and phlyctenular conjunctivitis. 

Irregular paralyses of the third, fourth, and sixth nerves of the 
affected side have been noted. 

Amaurosis, amblyopia, and functional blindness without retinal con- 
ditions to account for it, have been found to arise from notably advanced 
degenerative changes in the dental pulp, sight returning to the eye after 
loss of a diseased tooth. De Witt 2 records a most instructive case 
where temporary blindness was associated with septic apical peri- 
cementitis, disappearing after evacuation of the abscess, and reappear- 
ing when secondary inflammatory action arose in the pericementum. 
The ocular affection disappeared permanently and almost entirely with 
the loss of the tooth. The history of this case illustrates the important 
causal relationship of reflex disturbances with late pulp-degenerations ; 
for the blindness arose two months after some teeth were filled, and 
existed for twelve years before the septic apical pericementitis appeared. 

A careful examination of these and all other reflex disturbances 
shows that pulp-degenerations outnumber all other affections as causes. 
Many or most of the cases are recorded by general practitioners, who 
make no distinction between diseases of the pulp and those of the peri- 
cementum, but a reliable diagnosis of the conditions is made possible 
by the accompanying descriptions. 

Cases of ovarian and uterine neuralgia and sciatica and cases of 
obstinate pains in the toes and fingers have been traced to dental irrita- 
tion of some one of the varieties named ; the proof of association being 
disappearance of the pain with loss of the tooth. 

Motor Disturbances from Dental Diseases. 

Motor disturbances due to dental irritation may occur as recurrent 
or persistent contraction or paralysis of muscles, together with more or 
less general chorea ; in rare instances epilepsy and hystero-epilepsy. 
Twitching of muscles of the affected side of the face, ranging from 
slight affection of the occipito-frontalis, to recurring spasm of the ele- 

1 See Brubaker, American System of Dentistry, vol. iii., for very full and detailed dis- 
cussion of these subjects. 

2 Quoted by Brunton, Disorders of Digestion. 



DENTAL PAIN ARISING FROM OTHER THAN DENTAL SOURCES. 509 

vators and depressors of the lower lip, are far from uncommon phe- 
nomena attendant upon pulp-diseases. 

Contraction of the masseter muscle is a common accompaniment of 
retarded eruption of the lower third molar, which may be intensified 
until the condition is fitly termed trismus, in some cases of partial im- 
paction of the teeth. Partial trismus has been found due to a general 
overcrowding of the dental arch. 1 Records of cases of torticollis, due to 
dental diseases, are also given by Brubaker. 

Cases of facial paralysis, and cases of paralysis of one arm, of para- 
plegia and hemiplegia, and even of general paralysis, have been noted 
as disappearing after the extraction of diseased teeth. It is noteworthy 
that in these cases, as well as in several cases of tetanus recorded, the 
possibility of an infection entered into the pathogenesis of the nervous 
diseases. 

Stellwagen 2 records a case where symptoms of partial hemiplegia 
followed upon the operation of capping the pulps of two molar teeth ; 
the symptoms disappeared promptly upon extraction of these teeth. 

Cases of insanity arising from dental diseases have been recorded ; 
they were both maniacal and melancholic. In several of them a res- 
toration to a normal mental state followed promptly upon removal of 
the offending teeth. In some of these cases a pre-existing maxillary 
neuralgia directed attention to the teeth as possible sources of the 
nervous diseases. 

Dental Pain arising from other than Dental Sources. 

Conditions of pain the reverse of those discussed — i. e., pain defi- 
nitely or indefinitely located in teeth which exhibit no morbid condi- 
tions whatever — demand occasional attention at the hands of the dentist. 
These painful states are most commonly found in gouty patients, in 
whom the pain may have the character of pulp-pains, or of perice- 
mentitis. The pains may recur at intervals, and be associated with 
headache, constipation, etc. The gouty origin of the pains is indicated 
by the efficacy of sodium salicylate in their treatment, without any 
dental treatment whatever. 

Chronic malarial poisoning, as stated in the beginning of this 
chapter, may give rise to periodical attacks of maxillary neuralgia. 
As in the gouty cases, the constitutional cause of the disturbance is 
made clear through the therapeusis most effective, viz., the periodical 
recurrence of the pain leads to the inference of a malarial origin, and 
to the administration of quinin. 

Syphilitic pains in the jaws have a pericemental character, and other 
evidences of syphilis are present which point to a diagnosis. 

1 Brubaker. 2 Private communication. 



510 REFLEX DISORDERS OF DENTAL ORIGIN. 

Pains in or about the teeth are occasional accompaniments of dis- 
eases of the brain or its vessels, and of diseases of the uterus, kidneys, 
and bladder. 

Disease in any portion of the fifth cranial nerve may be referred to 
the teeth. 

Dental pain during pregnancy, without any direct evidence of dental 
disease, is relatively common. 

Disorders of the lower bowels, causing constipation, may give rise 
to pain referred to one or more teeth, the pain ceasing promptly upon 
the administration of an active evacuant. 






CHAPTER XXIX. 

INFECTIONS OF AND FROM THE MOUTH, AND STERILIZA- 
TION. 

The conditions found in the human mouth, as pointed out in Chap- 
ters III. and VI., are of a character which afford lodgement to, and 
opportunities for multiplication of, many forms of bacteria, both sapro- 
phytic and parasitic. The oral conditions are, however, not entirely 
constant, so that at different periods they may favor the develop- 
ment of some special bacterial forms more than others. The nature 
of these variations has not been made out, although their effects are 
indubitable. Again, the oral bacterial inhabitants are not constant 
as to species, for while there are many forms which appear to be 
invariable occupants of the oral cavity, many pathogenic forms are but 
accidental residents. Becoming resident, they may or may not develop 
according as they find in the mouth a suitable soil. The nature of 
what constitutes a suitable or unsuitable soil has not been determined, 
although in some cases extra-oral culture-experiments furnish some 
indications. 

Bacterial growth, as causes of dental caries and diseases of the 
pulp and pericementum, have been discussed in connection with those 
several diseases. It was shown that the pyogenic cocci are almost 
constant inhabitants of the human mouth. There appeared also evi- 
dence that some of the reflex disorders of distant parts are directly 
traceable to septic processes about the teeth, and, in addition to these, 
suppurative diseases in other parts become curable after removal of a 
septic tooth ; such conditions representing infection from a local dental 
infection, an important aspect of dental pathology. 

The infections arising from the growth of mouth-fungi are local and 
general. The phrase fungi is used in this connection, because other 
classes beside the fission-fungi (schizomycetes) are pathogenic also. Both 
the thread-fungi (hyphomycetes) and bud-fungi (blastomycetes) induce 
morbid conditions in the human mouth. 

The notable fungus of the blastomycetes, is the saccharomyces albi- 
cans ; this organism, when classified by mycologists as a thread-fungus, 
was known as the oidium albicans (Fig. 385). The growth of this 
organism illustrates forcibly the influence of soil on the growth of fungi. 
It does not occur in the mouths of healthy, well-nourished, and clean 
children with good surroundings. It is a disease of childhood, particu- 

511 



512 



INFECTIONS OF AND FROM THE MOUTH. 



larly of nurslings, and its occurrence is almost always confined to bottle- 
fed babies whose feeding-bottles are kept in an unclean condition. De- 



Fig. 385. 




Saccharomyces albicans, thrush fungus. (Miller.) 



bility of the oral tissues is established in consequence of the fermen- 
tations arising from the source named, furnishing a favorable condition 
for the development of the saccharomyces (oidium) albicans. The con- 
dition produced is known as thrush. The 
infection may be carried from one child to 
another, and if the fungus be brought in 
contact with an abraded mucous surface of 
an adult it may develop. 

The fungus burrows between the epi- 
thelial cells of the mucous membrane 
(Fig. 386), not beyond it. It first ap- 
pears in small spots, which coalesce, until 
large patches of a membranous-like growth 
cover extensive surfaces, spreading by con- 
tinuity to all of the mucous surfaces asso- 
ciated with the mouth. 

As bud-fungi flourish only in media of 
acid reaction, the use of alkaline washes is 
indicated in the treatment of this condition. 
Wiping the patches with dilute phenol 
sodique is also efficacious. 

The hyphomycetes, or thread-fungi, al- 
though associated with diseases of the 
human skin, have not had any pathologi- 
cal significance attached to them as regards 

Pavement-epithelium covered with the mouth. 
spores of the o'idium albicans. (Ch. 
Robin.) 

1 Miller, Micro-organisms of the Human Mouth. 




STOMATITIS. 513 

Infective Bacteria of the Mouth. 

Bacteria, being ever present, must always play a part in either origi- 
nating, modifying, or associating with all oral diseases. 

That the progressive decomposition of albuminous substances, always 
present in the mouth to a greater or less degree, by the action of sa- 
prophytic fungi, must give rise to derivatives of albumin, many of them 
toxic in effects, would be surmised even in the absence of experimental 
demonstration, a suspicion confirmed by experiment. Vulpian l pro- 
duced septicaemia by vaccinating animals with the saliva of a healthy 
man. Griffin 2 showed that the parotid saliva (pure) is harmless. The 
saliva, if boiled, exerts no toxic action, from which it is clear that it 
derives its toxic substances from the mouth. The saliva of individuals 
differs at times in the degree of its poisonous action. In some diseases 
it becomes intensely toxic. 

Of the many oral bacterial forms, some are cultivable and some 
are not; hence the specific effects of some are discovered, others are 
doubtful. 

With regard to local affections, other than those described in the 
body of this book, a bacterial causation has been made out in some, 
but in others it has not. 

Stomatitis. 

Definition. — By stomatitis is meant a catarrhal inflammation of the 
mucous membrane of the mouth. 

Varieties. — It may be localized, as in marginal gingivitis, or be 
diffuse ; and, again, be accompanied by localized tissue-destructions — 
ulcerations ; the character of the ulceration differs according to its prob- 
able causes. 

Occurrence. — Most of these diseases belong to the period of 
childhood, although localized ulcerative stomatitis may appear in the 
adult. 

Causes. — The causes of stomatitis are so many and varied as to 
suggest a classification under heads according to assignable causes. 
While it is true that bacterial infection has not been shown to be 
a direct cause of all of these conditions, some degree of causal rela- 
tionship is probable in all of them. The disease may, however, be 
included under two heads according as they are or are not localized, and 
necrotic. The less localized cases appear as a diffuse catarrhal affec- 
tion, affecting wide areas of the oral mucous membrane ; the others 
appear as spots of localized tissue-destruction attended by surrounding 
hyperemia. 

1 Quoted by Miller. a Ibid. 

33 



514 



INFECTIONS OF AND FROM THE MOUTH. 



Catarrhal 
Stomatitis 



Local 



Symptomatic 



f Simple. 

v Infectious . . . . 

Eruptive fevers. 
Syphilis. 
Tuberculosis. 
Typhoid fever. 



Drug-action . . . J 



( Fermentations. 
i Diphtheria. 
^ Gonorrhoea. 



Ulcerative 
Stomatitis 



Local 



Iodids. 
Mercury. 
Lead. 
(^ Pilocarpin. 



Aphthae. 

Thrush. 

Noma. 
j Herpes. 
j Syphilis 
L (primary). 

c Q i . r f Secondary 

[ bypnihs <f 



Symptomatic 



t Tertiary. 



*] Tuberculosis 
(^ (local). 



SIMPLE LOCAL CATARRHAL STOMATITIS. 

The general symptoms of catarrhal inflammation — heat and swelling, 
with deepened color of the mucous membrane, followed by increased 
secretion and exudation — attend several types of oral irritation, such 
as the irritation induced by erupting teeth, particularly of the deciduous 
teeth. Inflammation of any degree may follow the taking into the 
mouth of caustic chemical substances, such as caustic alkalies, mineral 
acids, carbolic acid, etc., which are occasionally taken by children. 
Other irritant drugs, and very hot fluids may produce similar results. 
General catarrhal stomatitis is a frequent affection of confirmed smokers, 
and of drinkers of distilled liquors. 

The cure of these conditions consists in the removal or neutralization 
of the cause, and the use of local sedatives and antiseptics to allay irri- 
tation and prevent infection. The most effective method of treating 
the inflammatory condition is by antiseptic sprays, such as diluted 
Dobell's solution, followed by sprays of strong solutions of potassium 
chlorate. If much pain exist, phenol sodique is an admirable sedative 
antiseptic, used in 10-20 per cent, solution, as a spray. 

INFECTIVE LOCAL CATARRHAL STOMATITIS. 

This in some degree is a common, perhaps the necessary, antecedent 
condition to many of the ulcerative forms of stomatitis. It is probable 



STOMATITIS. bib 

that many of the cases of stomatitis found in infants, children, and 
adults are due to unusual fermentations occurring in the mouth. Chil- 
dren whose nursing-bottles are not kept clean ; those who at a later age 
suffer from neglect of the teeth and from the effects of improper food ; 
adults in whose mouths dental diseases are widespread, and whose oral 
hygiene is very faulty : all exhibit abnormal conditions of the oral 
mucous membrane — more or less swelling, softness, and deepened color 
of the mucous membrane, a coated tongue, and offensive breath, with 
an increase of oral secretions. 

The complexus of oral symptoms is commonly, and also by the 
general practitioner, regarded as symptomatic of gastric, intestinal, and 
hepatic disorders, as doubtless they are, but the causal relationship is 
in many cases probably the reverse of that implied in such opinions, for 
it is probable (see later) that the disturbances of digestion are fermenta- 
tive in character, and the organisms causing them find their way to the 
stomach from the mouth, which was first affected. The treatment of 
this condition consists in the correction of its causes, their non-repetition, 
and the continued use of oral antiseptics. 

While the point of first attack of the diphtheria bacillus is most marked 
about the soft palate and tonsils, the false membrane forming there and 
spreading to the pharynx, more or less general inflammation of the 
oral mucous membrane also occurs. The gonococcus may be lodged in 
some portion of the oral cavity and excite its specific effects upon con- 
tiguous mucous membranes. 

SYMPTOMATIC CATARRHAL STOMATITIS. 

Stomatitis in its catarrhal form is usually associated with the early 
and later stages of the eruptive fevers, scarlet fever, smallpox, etc. In 
scarlet fever and smallpox evidences of direct infection of the mouth 
exist and the inflammatory reaction is pronounced. 

Catarrhal stomatitis is one of the manifestations of secondary and 
tertiary syphilis, antedating the appearance of tissue-necrosis (ulcera- 
tions'). 

More or less catarrhal stomatitis, confined, it may be, to the mucous 
membrane of the gums, is common in the mouths of phthisical patients ; 
this condition exhibits no evidence of direct association of the local 
development of the bacillus of tuberculosis, because no tubercular 
ulcers may arise or threaten. 

The stomatitis of typhoid fever may be regarded as an almost essen- 
tial feature of the disease. 

The effects of drug-elimination by the oral tissues have been already 
discussed (see Chapter XXIV.). 



516 INFECTIONS OF AND FROM THE MOUTH. 

ULCERATIVE STOMATITIS. 

It has been customary to describe ulcerative stomatitis as simple and 
infective ; in all probability these ulcerations are always infective. 
Like catarrhal stomatitis the ulcerative disease may have only a local 
significance or be indicative of some general disease. 

Ulcerative Stomatitis of Local Significance. — The more usual or 
infantile forms of these disorders are a sequel of catarrhal stomatitis, 
at least of an acquired debility of the oral tissues, and their primary 
cause is, therefore, the cause producing a condition of mucous mem- 
brane which permits the growth of infective organisms. One of these 
diseases, thrush, has already been described. The others, aphthae, herpes 
labialis, and noma, are all probably due to the action of organisms. 

Aphthae. — This affection is common in its isolated form, as the canker 
sore. In the catarrhal stomatitis of children, during or after dentition, 
multiple sores frequently make their appearance. The condition can 
best be studied when it appears as an isolated sore in the mouth of the 
adult. The most common situation of the sore is at the junction of 
two mucous surfaces, such as that of the gum with the lip or cheek, or 
that of the floor of the mouth with the gum or tongue. Redness dif- 
fused over a limited area, followed by a nodular hardening, occurs, 
during which local pain is annoying ; the centre of the hardened area 
breaks, forming a raw surface, which quickly acquires a rough white 
coating which is easily removable. The sores are very painful. 

This condition follows so constantly upon the taking of very indi- 
gestible food, such as lobster, Welsh rarebits, etc., that acute indigestion 
must be regarded as having some causal relationship with it. It is also 
of frequent occurrence in the mouths of dyspeptics ; that form of 
gastric disturbance attended by a deficiency of hydrochloric acid in the 
gastric juice appears to have a constant association with it. 

The appearance of ulcerative stomatitis in children, together with 
its treatment, was discussed in the chapter on Dentition. 

The general treatment of these ulcerations appearing in the mouths 
of children is the administration of a laxative, and the subsequent 
administration of listerine, gtt. x, every two hours. Locally the 
mucous membrane is to be sprayed with pyrozone, followed by sprays of 
strong solutions of potassium chlorate. 

Localized aphthous patches in the adult are promptly relieved by the 
administration of calomel, gr. ij at night, followed in the morning by a 
mild saline. The local sore is dried and touched with pure carbolic 
acid. The administration of alkalies before meals, and hydrochloric 
acid after meals, usually remedies the gastric condition, unless it be of 
long standing. 



STOMATITIS. 



517 



A variety of aphthous sore is called, from the anatomical situation 
of the ulcers, follicular stomatitis. Irritation and swelling of the 
mucous follicles in the palatal, buccal, and labial mucous membrane are 
accompanied by more or less localized inflammation ; the follicles 
become ulcerous, the small ulcers having a uniform size. This condi- 
tion quickly disappears under the treatment advised for ulcerative 
stomatitis. An indication of the bacterial origin of all of these dis- 
turbances is seen in the efficacy of antiseptics used in their treatment. 

Noma, Cancrum Oris, Gangrene of the Mouth. — In ill-fed, 
ill-nourished, and ill-kept, cachectic children, the debilitation of the oral 
tissues may exceed the grades given, and a disease probably bacterial in 
origin may arise which leads to widespread necrosis of the cheeks and 
maxillae. The condition is called gangrene of the mouth, noma, or can- 
crum oris ; the latter term has been applied to the less severe varieties. 

This disease may make its appearance as an ulcer at the junction of 
cheek and gum ; in other cases a severe stomatitis arises without a 
primary ulcer. A greater or less extent of the cheek acquires a board- 
like hardness, becoming livid ; the overlying mucous membrane breaks, 



Fig. 387. 




Noma (J. Lewis Smith.) 



exhibiting a large slough. The necrosis extends toward cheek and jaw, 
destroying further tissue. The sloughs undergo putrefactive decom- 
position, emitting a stench. The destruction of tissue may be arrested, 
or may proceed, destroying in a few days the entire cheek and bony 



518 



INFECTIONS OF AND FROM THE MOUTH. 



tissues. In the more severe cases the disease is almost invariably fatal, 
because the extent of the tissue-destruction bears a constant relation to 
the underlying debility of the patient. It will be seen that the disease 
resembles malignant pustule or carbuncle in several of its features. 

While no specific organism has been isolated as pathogenic of this 
condition, Schimmelbosch l found a bacillus (pure culture) upon the 
borders of the necrosis, which may prove pathogenic of noma. 

These cases are purely medical, so that their full discussion is not 
warranted in these pages. The principle of treatment is to improve 
the general condition of the child, destroy the probable infection in the 
borders of the still vital tissue, and promote sloughing of the necrosed 
tissue. 

Syphilitic Affections of the Mouth. — The recognition of syphilitic 
lesions about the mouth is of vital importance to the dental operator, 
first, because by the recognition he may take steps to prevent the car- 
riage of infection to innocent patients ; and, secondly, that he may avoid 
inoculation of himself by the poison. 

In the minds of many, syphilis is associated with the lower class of 
persons, who are confirmed debauches. While it is undoubtedly true that 
its prevalence is most marked in this class of persons, it appears, and 
with horrible frequence, in persons who would be little suspected of 
having such infection. The operator is to be guided in his opinions 
and precautions in this matter, not by the social status of the patient, 
but by the nature of the morbid conditions existing. 

Syphilis is usually divided into three stages, primary, secondary, and 
tertiary ; to these may be added a fourth stage, viz., in patients who 
have been discharged as cured mild manifestations of disorders, par- 
ticularly of the skin and mucous membranes, make their appearance 
from time to time, and disappear promptly upon the administration of 
iodids. 

The first stage of syphilis — primary syphilis — consists in the forma- 
tion of the primary sore or chancre, and the involvement of the nearest 
lymphatic glands. Secondary syphilis is attended by fever, eruptive 
inflammations of the skin, inflammation and superficial ulcerations of 
mucous structures. In tertiary syphilis destructive inflammation of 
the skin, mucous membranes, and connective tissues occurs, together 
with the formation of specific tumors — gummata. 

Some difference of opinion exists among syphilographers as to the 
relative infective power of the secretions from the several lesions of 
syphilis. All are agreed, however, that the secretions from the second- 
ary lesions observed in and about the mouth are highly infective. It is 
the part of prudence to regard all syphilitic lesions as infective. All 

1 Miller, Dental Cosmos, Sept., 1891. 






SYPHILITIC AFFECTIONS OF THE MOUTH. 519 

these stages of syphilis may be seen in the human mouth. It is to be 
remembered that if the mucous membrane of the mouth be infected 
from a mucous patch (a secondary lesion), the acquired disease will 
appear, not as a mucous patch, but as a chancre. It is from mucous 
patches that infection is most to be feared. 

Primary Syphilis of the Mouth. — Causes. — The primary lesion 
of syphilis, chancre, when found in the mouth is a consequence of direct 
infection from a syphilitic. The infection occurs from contact of the 
mucous surface of the mouth with a syphilitic lesion upon another per- 
son : it has been transmitted by kissing : it may occur from using a 
glass or cup previously used by a syphilitic, by smoking cigars or 
cigarettes which have been made by syphilitic cigarmakers, who have 
applied the tongue to the tobacco in attaching the wrapper. Any of 
the articles named, or the contact of any article which has been in 
contact with a syphilitic lesion, if brought in contact with an abraded 
mucous surface may cause infection. 

The infection may be transferred from patient to operator if the 
fingers have any abraded surface, or if the surface is broken accidentally 
by an instrument. Infection may be transmitted from one patient to 
another by any instrument, appliance, or article used by the syphilitic 
being afterward used by an innocent person. Drinking-glasses, mouth- 
mirrors, exploring-instruments, rubber-dam, rubber-dam clamps, saliva 
ejector tubes, lancets, forceps, or any other instruments may be the 
medium of communication. During and since the time of Hunter the 
use of teeth from syphilitic patients in plantation operations has been 
a clearly recognized medium of communication. 

Appearances and Diagnosis — " The primary lesion of syphilis never 
makes its appearance before ten days after infection ; the maximum 
period is about ninety days ; the average is twenty-one days." l 

It usually appears as a single, elevated, hard papule. In cases of dental 
infection, most frequently about the lips, the papule loses its epithelial 
coating after some days. The induration surrounding the papular mass 
increases until the papule, which is now raw and in a process of ulcera- 
tion, appears surrounded by a ring of cartilaginous hardness. This indu- 
ration is the one distinguishing feature of the chancre, which is not 
painful. In about a week after the appearance of the primary sore, 
swelling of the submaxillary lymphatic glands is observed. In case the 
chancre appear upon the tongue, the subhyoid lymphatic glands are 
swollen. 2 Unless pyogenic infection have occurred, the lymphatic 
involvement is not inflammatory, there being no pain present. In from 
three to four weeks the sore disappears, leaving no signs of its site in 
some cases ; in others, some induration may persist. 

1 Gross, System of Surgery. 2 Park, Surgery. 



520 INFECTIONS OF AND FROM THE MOUTH. 

The diagnosis of this condition is the important con side ration , so far 
as the dental practitioner is concerned, its treatment being the province 
of the general surgeon. 

The elevation of the sore, its induration, and, if obtainable, the time 
of inoculation, are diagnostic data. The sore is single, and there is 
hard, nodular, painless swelling of the neighboring lymphatics. A single 
ulcer of ulcerative stomatitis may in some degree simulate the appear- 

Fig. 388. 




Chancre of the lip. 

ance of a very small chancre. It may exhibit slight induration, but its 
irregular form, situation, painfulness, and the usual absence of lymphatic 
involvement, together with its prompt disappearance after sterilizing 
the mouth and cauterizing the ulcer, will differentiate the two sores. 
If the chancre be upon the tip or sides of the tongue, where it is sub- 
jected to irritation, it may become very large and bear a close resem- 
blance to epithelioma of that organ. 

It is a wise precaution to view all sores about the mouth as possibly 
infectious. All errors of diagnosis in this direction will be more than 
compensated for by the assurance of non-transference of infection. 

Secondary Syphilis of the Mouth. — The secondary manifes- 
tations of syphilis are observed in and about the mouth, no matter 
what the location of the primary lesion may have been ; they are the 
result of a general, not a local, infection. 

Secondary affections of the mucous tissues appear in from four to 
twelve weeks after the appearance of the primary lesion. Sore throat, 
due to inflammation of the mucous membrane of the pharynx and parts 
about, is almost constant ; together with syphilitic hoarseness, due to 
the extension of the affection to the mucous membrane of the larynx. 

The appearance of copper-colored areas upon some portion of the 
mucous membrane, on the tonsil, pharynx, soft palate, lips, or bucco- 
labial surface, precedes the loss of epithelium over these surfaces, which 
soon occurs, forming the most virulently contagious lesion of syphilis, the 
mucous patch. The patches become covered with a grayish-white pasty 



SYPHILITIC AFFECTIONS OF THE MOUTH. 521 

covering, resembling the ulcerations of non-specific stomatitis. So 
close is the resemblance that a differentiation can only be made at times 
by additional evidences of secondary syphilis. Single patches may 
coalesce, forming large irregular areas covered by a grayish-white pel- 
licle. These patches are rarely painful. Ulcerations having ragged, 
irregular outlines may appear at the sites of the original patches or in 
other situations, and exhibit a tendency to spread. 

The diagnosis of the condition is determined by a discovery of other 
lesions of secondary syphilis ; skin-eruptions, falling out of the hair 
(alopecia), and the areas of copper-colored eruption upon the mucous 
membrane of the pharynx and soft palate. 

Hugenschmidt l has observed among syphilitics, who presented no 
local lesions, the frequent nocturnal occurrence of indefinitely located 
dental pains, spreading to the palatal region. 

Tertiary Syphilis of the Mouth. — The syphilides of the 
secondary stage arise in, and are confined to, the mucous and dermal 
structures ; those of the tertiary stage arise in the deep connective tis- 
sues, and are frequently associated with periosteum. 

Tertiary lesions, as seen by the dentist, are usually in the form of 
ulcers of, first, the soft or hard palate, and of the tongue or lips. In 
the earlier stages hard nodular formations may be noted as antecedents 
to the ulcerations. Chronic periostitis of the palatal processes may 
occur, leading to the formation of localized thickenings. In other cases, 
in the soft palate, upon the tongue, or in the hard palate, localized swell- 
ings may occur ; the overlying mucous membrane breaks, establishing 
an ulcer, which may perforate the soft palate, and destroy a portion of 
the palatal process, or form large ulcers on the tongue. These lesions 
appear in from two to five years after the secondary manifestations. 

Although there is much doubt as to the degree of infectiveness of 
these tertiary lesions, precautions as to sterilization should be taken as 
with the primary and secondary lesions. A defined, ragged ulcer occu- 
pying the hard or soft palate, which has persisted for a long time, 
should always be viewed with suspicion, and a search be made for other 
evidences of syphilis. 

These ulcerations appearing upon the side of the tongue may closely 
simulate epithelioma of that organ. The confusion is increased if, in 
consequence of the presence of jagged teeth, a continuous irritation is 
excited. Moreover, leukoplakia of the cheeks, a diagnostic sign of 
incipient epithelioma, frequently accompanies tertiary syphilis. In 
some cases an absolute diagnosis is only made by noting the disappear- 
ance of the local lesion following the administration of iodids, the 
specific treatment of tertiary syphilis. 

1 Dental Cosmos, 1892. 



522 INFECTIONS OF AND FROM THE MOUTH. 

The existence of tertiary syphilis is of great clinical importance to 
the dentist in that a condition of lessened resistance of tissues is estab- 
lished, and disease-processes which in the healthy person are compara- 
tively circumscribed, in the syphilitic run a riotous course. A septic 
pericementitis by extension may involve a wide area of periosteum, 
leading to extensive maxillary necrosis. 

Tuberculosis of the Mouth. — The bacillus of tuberculosis, under 
favorable conditions, develops in the tissues of the mouth, producing 
its characteristic lesions. Finding a suitable soil, such as is furnished 
by the heredity which predisposes to phthisis pulmonalis, the bacillus 
may find entrance to the deeper tissues from the mucous membrane of 
the mouth and excite tuberculosis in the deep structures, the bone, etc. 
What part is played by local oral and dental lesions in tuberculosis of 
distant parts, by establishing pathways for the entrance of the bacilli 
into the circulation, is at present conjectural, but that such infections 
occur is very probable. 

Actinomycosis. — The condition produced by the development of 
the ray-fungus, the actinomycosis, in the lower jaw and cervical regions 
of cattle and swine — lump-jaw — is not unknown in human beings. 

Miller 1 gives 203 cases reported in German medical literature be- 
tween 1886 and 1891. In at least 120 of these cases the point of 
entrance of the fungus was found to be in the region of the mouth or 
throat. Actinomycosis-threads have been repeatedly found in the saliva 
and in carious teeth, and notably in the tonsils. Whether the path of 
entrance to deeper structures is ever through carious teeth is undeter- 
mined, but certainly lesions or wounds about the mouth furnish an 
entrance. 

General Septic Diseases of Dental Origin. 

The effect of the existence of dental diseases upon the body at large, 
particularly as regards secondary infection, is a matter increasing in 
importance as the possibilities of their connection are made out. At 
present, the organisms of greatest demonstrable pathological interest are 
the pyogenic cocci. The almost constant presence of these organisms in 
the mouth, carried thence into the pharynx, posterior nares, larynx, and 
lungs, furnishes the reason for the pyogenic inflammations which occur 
in these organs. The diplococcus of pneumonia, a frequent organism, 
but waits a favorable opportunity to establish high inflammations and 
fibrinous exudations in the lungs, and possibly in other structures. 

The most important clinical associations of dental with general 
infections, are diseases of the pericementum. The pulps of teeth, 
having no lymphatics, do not appear to take up and transmit the 

1 Dental Cosmos, 1891. 



DENTAL STERILIZATION, 523 

products of the action of septic organisms ; but while the evidences 
of such absorption, involvement of the neighboring lymphatics, are not 
present, it must be remembered that the veins may transmit the poison, 
and, in addition, may perhaps convey organisms from a diseased but 
still vital pulp to distant parts. When, however, the pulp is dead and 
the pericementum is invaded, there is no doubt of general infection 
from this local source. More or less septic intoxication is a common 
attendant upon severe septic apical pericementitis, and septicaemia ac- 
companied by inflammation of the neighboring lymphatic glands is 
of sufficient frequency to emphasize the need of the vigorous antiseptic 
treatment recommended in all of these cases. 

Pyaemia is far more uncommon. 1 Pyogenic organisms, gaining access 
to the blood-current from the local source of infection, establish sup- 
puration in distant parts ; in other parts of the bone, or in other bones 
(osteomyelitis), in the lungs, meninges and substance of the brain. One 
case 2 has been reported where abscess of a toe, ear, and forearm ceased, 
and recovery took place after treatment and filling of septic root-canals. 
Several cases are tabulated by the same author in which extensive 
necrosis and death resulted from pyaemic infection from septic peri- 
cementitis. Some of these cases recorded were associated with acute, 
some with chronic septic pericementitis. 

In addition to the usual pyogenic cocci, Miller has isolated several 
forms of cocci, bacilli, and spirilla, forming products, which, if injected 
into the circulation of animals, cause death from septicaemia in from 
hours to days. As many of these forms may be brought into relation 
with deep parts by the anatomical conditions created by pulp-death, 
the possibilities of many types of infection via pulpless teeth are 
evident. 

The possibilities of infections through the conditions established in 
the several forms of pyorrhoea alveolaris should not be forgotten. 

The pockets formed by the soft tissues overhanging lower third mo- 
lars whose eruption is impeded invite the passage of septic organisms to 
deep parts. Local pyogenic infections are common in these cases. 

Dental Sterilization- 

It must ever be borne in mind that the dental operator constantly 
works in a field of infection, and unless extraordinary precautions be 
taken every instrument which touches this field — the fingers of the 
operator, his mirrors, glasses, napkins, rubber-dam, rubber-dam clamps 
— becomes immediately infected as soon as it is brought in contact with 
the mouth of the patient. The likelihood of infection varies with the 
patient and the particular instruments ; mouth-mirrors, rubber-dam 

1 Miller, Dental Cosmos, 1891. 2 Ibid. 



524 



INFECTIONS OF AND FROM THE MOUTH. 



clamps, scalers, and all instruments used in the treatment of pulp- 
canals, are likely to become more promptly and extensively infected 
than other instruments. Again, the forms of the instruments determine 
whether or not increased opportunity is given for the retention of infec- 
tive material. The fingers of the operator may be the medium through 
which infective material is transferred from one patient to another. 
Infection may be carried from superficial areas of the mucous mem- 
brane of the mouth, from the enamel and the saliva, into deeper struc- 
tures, where conditions are favorable for the development of sepsis. 

The scheme for dental sterilization, therefore, includes the steriliza- 
tion of the operator, instruments, apparatus, appliances, etc., used in 
operations, and the sterilization of the field of operation prior to 
operating. 

THE OPERATOR. 

Extreme personal cleanliness upon the part of an operator is clearly 
the first step in asepsis. The best class of dentists are exceedingly neat 
as regards personal habits : daily bathing, care of the nails and of the 
skin, and immaculate linen, form as much a part of the day's labor as 
dental operations per se. The virtues of soap and water, wherever they 
may be applied, are regarded as a very important item in preventing 
infection. 

Linen which has been boiled prior to wearing may be regarded as 
safely sterile ; so that the matter of personal sterilization relates to the 
hands, particularly to the finger-nails. The space under the nails is a 
favorable habitat for many organisms, notably the pyogenic cocci, the 
staphylococcus pyogenes aureus being commonly present in this situation. 

It has always been advised that the finger-nails be trimmed short, 
and be made smooth to avoid mechanical injury to the soft tissues of 
the patient. Since the advent of aseptic and antiseptic surgery these 
precautions have an additional significance ; nails kept short and smooth 
may be more readily cleansed than if long and ill-kept. The nails 
should be cut with a sharp knife-blade so that they nowhere project 
beyond the tips of the finger. Their mechanical cleansing should be 
done with smooth instruments, not sharp knife-blades ; the latter produce 
rough surfaces, which furnish spaces for lodgement of bacteria. There is 
but one effective method of washing beneath the nails ; it is that followed 
by the general surgeon : after dipping the soap in water as hot as can be 
borne by the hands, all of the finger-nails should be made to scrape the 
soap until the spaces under the nails are filled with soap. After this, 
coarse hand-brushes are used to scour every part of the hands with soap 
and water as hot as can be borne. Special nail-brushes are next used 
to scrub beneath the nails, driving out piecemeal the soap-masses there. 
The general surgeon continues the scrubbing until the nails are scrupu- 



DENTAL STERILIZATION. 525 

lously clean. The soap usually used is Castile, or soap made from palm 
oil, etc. ; but antiseptic soaps may be substituted with advantage. 

Sterilization of the cleansed hands is insured by immersing them in 
antiseptic solutions, such as a 1 : 1000 solution of mercuric chlorid. The 
hands should be sterilized after treating each patient. If the patient 
dismissed have possessed an unusually septic mouth, or have been a 
syphilitic, for example, the time for hand-cleansing and sterilization is 
to be prolonged ; if syphilitic, every instrument used is transferred to 
separate vessels containing antiseptic solutions, and the hands are viewed 
as highly infected ; they are scrubbed with mercuric chlorid solutions 
to prevent personal infection or the carriage of infection. 

STERILIZATION OF APPARATUS. 

The scrupulous cleanliness of the operating-chair, whose head-rest 
should receive frequent changes of boiled linen coverings, metallic parts 
rubbed, and general covering cleansed ; the cleansing, polishing, and 
sterilizing of cuspidores ; the changing of lining coverings upon instru- 
ment-tables, etc., are part of the general scheme of sterilization. The 
floor of the operating-room also requires attention ; instead of being 
covered with carpet, it is preferable to have it made of parquetry 
material, lacquered hard wood, over which rugs are laid, which may 
be removed from the room for cleansing, the floor proper being scrubbed. 

Glassware, such as tumblers, may be effectually sterilized by boiling. 
Linen napkins are also sterilized in the same manner. Napkins used 
about the mouth are certain to become infected, so that their boiling 
should be prolonged at least fifteen minutes. For many operations it is 
preferable to substitute strips of muslin for linen napkins, which after 
being used may be thrown away. 

If a hydraulic saliva-ejector be used, the glass mouth-tubes should 
be changed for each person, a sterilized tube being immediately sub- 
stituted as soon as a patient leaves the chair. These tubes should 
receive prolonged boiling before a second use. At the close of each day 
a large cup should be filled with an antiseptic solution, which is to be 
drawn through the tubing of the ejector to keep it in a reasonably 
aseptic condition. 

Rubber-dam may be sterilized by boiling water, but it is more safe and 
cleanly to use a new piece for each patient. The possibilities of infec- 
tion through this medium are great, particularly in syphilitic cases. 

STERILIZING INSTRUMENTS. 

The sterilizing of instruments comprises their mechanical cleansing 
and the use of germicides ; steam heat and antiseptic drugs are both 
employed for this purpose. Steam heat being the most convenient and 



526 



INFECTIONS OF AND FROM THE MOUTH. 



certain sterilizing agent, is used wherever it cannot produce injury to 
instruments. 

All instruments should be kept in a highly polished condition, being 
rubbed with crocus cloth at the end of each day's use. Excavators, 
explorers, and pulp-canal cleansers should be mechanically freed from 
visible foreign matter by rubbing their points with a wire brush. A 
wire brush should be used to cleanse all excavating-burs which have 
been in use. To sterilize the mechanically cleansed instruments they 
are boiled in water to which 2 per cent, of sodium carbonate has been 
added to prevent rusting. 

Mouth-mirrors, of which there should be several, require special 
care. Their edges afford favorable lodging-places for bacteria, and 
hence they require long boiling. Miller l found that the usual antiseptic 
solutions used cold acted as very imperfect sterilizers, but at the tem- 
perature of boiling their efficacy was markedly increased. 

Extracting-forceps require careful mechanical cleansing and pro- 
longed boiling after each use, for perhaps more cases of infection, and of 
many kinds, have resulted from dirty forceps than from all other causes 
combined. 



STERILIZING THE FIELD OF OPERATION. 

To insure sterilization of the field of operation antiseptics should be 
used freely about the mouth prior to operating. The thoroughness of 
the sterilization will depend in great degree upon the personal habits 
of the patient. If by the systematic use of the agents and measures 
described under the prophylaxis of caries, the patient's mouth be kept 
in a reasonably aseptic condition, sterilization of the oral cavity can be 
accomplished with sufficient readiness. The choice of antiseptic will 
depend in great degree upon the state of oral hygiene ; in ill-kept 
mouths, with deposits of foreign materials about and between the teeth, 
on the gums and tongue, much more active and penetrating germicides 
will be required than if the parts are clean. The presence of putre- 
factive decomposition in the mouth, made evident by ill odors, amid 
which that of hydrogen sulfid may be detected, needs for its treatment 
the immediate and free use of preparations from which nascent chlorin 
or nascent oxygen may be disengaged. No operation or even examina- 
tion should be begun in such cases before a claret-colored solution of 
potassium permanganate, or a strong solution of hypochlorites (medi- 
trina diluted), has been freely used by the patient. Many operators 
keep a stock of inexpensive tooth-brushes for such cases, which are 
thrown aAvay after the patient has used them, who is directed to scrub 
the teeth well with brush and the antiseptic solution. 

1 Dental Cosmos, 1891. 



DENTAL STERILIZATION. 527 

The routine practice of scaling and polishing the teeth and pre- 
scribing an antiseptic mouth-wash prior to the commencement of a 
series of sittings, is to be highly commended. To sterilize a compara- 
tively clean mouth sufficiently to begin dental operations, hydrogen 
dioxicl may be used ; it should be held in the mouth and pumped about 
by the movements of the lips and cheeks for a minute or longer. 

If ulcerations or inflammatory conditions exist, the sterilization is 
to be prolonged, using such agents as meditrina. If a suspicion of 
syphilis exist, not only should the mouth be freely washed with strong 
antiseptics, but special instruments should be used, preferably an old 
set, kept sterilized and used only in special cases. If the hands of the 
operator have abrasions or irritated spots, they should be covered with 
collodion, or, better, the examination should be referred to one whose 
skin-surface is unbroken. 



SECTION VII. 

DENTAL PHARMACOLOGY AND DENTAL 
MATERIA MEDICA. 



DENTAL PHARMACOLOGY. 

A dental materia medica includes a description of the agencies 
which are employed in the treatment of oral diseases ; dental pharma- 
cology considers the mode of action and composition of these substances 
and agencies. The intelligent use of drugs, as of any therapeutic 
resource, is based upon a primary knowledge of their chemical and 
physical properties, together with a familiarity with the exact nature of 
the altered physiology the practitioner is called upon to remedy. A 
rational therapeusis is founded upon the utilization of the specific prop- 
erties of remedial agents to combat morbid conditions whose character 
has been clearly determined. 

If generalizations be made of the several disease-states described in 
the body of this volume, it will be seen that the dental practitioner 
meets with three great classes of conditions requiring treatment : 

First, a large majority of diseases of the teeth and associated parts 
are bacterial in origin — are due to septic influences ; hence the first 
group of agents of dental practice are those used to combat septic con- 
ditions, or antiseptics. 

The second, class of conditions demanding relief are those in which 
pain is a prominent symptom ; hence the second class of agents to be con- 
sidered are those used for the relief of pain — anaesthetics or analgesics. 

The third group of conditions, viewed as a class, comprises those 
characterized by a relaxation of soft tissues and a passive dilatation of 
their bloodvessels ; hence the third group of dental remedies is that 
of the astringents, or substances which have the power to bring about 
contraction of relaxed parts. 

Nearly all of the agents which have been found to possess distinct 
therapeutic value in dentistry may be placed under one of these three 
heads, although an agent of one group may possess properties of all 
three classes. 

Some few of the drugs and agents employed in dental therapeusis 
cannot be properly classified under any of the three heads named, but 

34 529 



530 



DENTAL PHARMACOLOGY AND MATERIA MEDICA, 



these, as well as all other therapeutic agents, may be included under 
two heads — stimulants and sedatives ; that is, all agents used in general 
or special medicine are employed either to exalt or to depress some one, 
or more, vital functions of some organ or tissues of the body. 

Antiseptics. 

Antiseptics are agents which prevent the action of pathogenic organ- 
isms or of their products upon the living body. Members of this great 
group differ in their chemical properties and mode of action. Under 
the head of antiseptics are grouped sub-classes of remedies, named in 
accordance with their mode of action against septic influences. They 
may act by destroying the vitality of the infective organisms ; a sub- 
stance or agency having this power is termed a germicide. They may 
act by chemically destroying the poisons formed by bacteria without 
necessarily killing the organisms. Conditions may be established in 
the cells of the body which inhibit the growth of organisms. Any 
agent which has the power to remedy an existing infection is called a 
disinfectant. It is seen, therefore, that a distinction may be drawn 
between an antiseptic, a germicide, and a disinfectant. A germicide is 
both antiseptic and disinfectant, but antiseptics and disinfectants are 
not necessarily germicides. Again, an antiseptic acts to prevent as 
well as remedy infection ; a disinfectant implies an existing infection. 
Under this head should be grouped deodorants, agents that have the 
power of destroying objectionable odors which arise during putrefactive 
processes, and from other sources. A true deodorant operates by 
chemically destroying the malodorous substance ; for example, chlorin 
vapor acts as a deodorant by abstracting the hydrogen from such a sub- 
stance as hydrogen sulfid, destroying its chemical identity and therefore 
the original odor : 



H 2 S + Cl 2 



2HC1 + S. 



Bromin, iodin, and nascent oxygen act after the same manner. Most 
of the deodorants, and all of those named, are active antiseptics, many 
of them germicides, destroying not alone the organisms, but also their 
waste-products. Agents such as carbolic acid and the cresols are not 
true deodorants, although they destroy the organisms which are the 
primary cause of the offensive odors. 

Nearly all of the antiseptics employed in the treatment of dental 
diseases may be grouped under eight heads : 



First. 



Salts of metals 



Zinc chlorid ; mercuric chlorid ; 
silver nitrate, citrate, and lac- 
tate ; copper sulfate. 



ANTISEPTICS. 



531 



Second. 



Third. 



Fourth. 



Fifth. 



Sixth. 



Alcohols and their de- 
rivatives 



The halogen group and 
their compounds . . 



Mineral acids 



Solutions from which 
nascent oxygen is 
evolved 



Seventh. 
Eighth. 



The essential oils 
Physical agencies 



Organic acids . . 



The caustic alkalies . < 



I 



Ethyl alcohol ; methyl alcohol, 
and its derivative formal - 
dehyd ; phenyl alcohol, in- 
cluding all allied substances, 
such as creasote, the cresols, 
creolin, and lysol. 

Iodin and its preparations, in- 
cluding iodoform, nosopben, 
aristol, iodol, antinosin ; solu- 
tions from which nascent 
chlorin may be evolved — 
hypochlorites ; bromin is not 
used as a dental disinfectant. 

Sulfurous, sulfuric, hydro- 
chloric, chromic, and boric 
acids; solutions of hyposul- 
fites, which act by virtue of 
their sulfite radical, may be 
included. 

Trichloracetic, lactic, and ben- 
zoic. 

Metallic sodium and potassium 
in alloy (kalium-natrium) . 
the hydrates and carbonates 
of sodium and potassium ; 
sodium dioxid ; aq. ammonise 
fort. 

Hydrogen dioxid in watery 
and ethereal solutions from 
3 per cent, to 25 per cent, 
strength ; solutions of so- 
dium dioxid ; potassium per- 
manganate. 

Cajuput ; cassia ; cinnamon ; 
cloves (and eugenol) ; eu- 
calyptus ; gaultheria ; myrtol ; 
and thyme. 

Heat, dry and moist. 



Each of these groups exhibits distinct modes of germicidal action, 
in accordance with their chemical properties. 

The varied conditions under which bacteria are found will modify the 
choice and application of antiseptics and germicides. To act as a direct 



532 DENTAL PHARMACOLOGY AND MATERIA MEDICA. 

and prompt germicide the agent must be brought into intimate con- 
tact with the organisms. There are physical obstacles, varying under 
many conditions, which antagonize the desired end. Many forms of 
bacteria are enclosed in a resistant coating or cell-wall ; in addition 
to this, several forms unite into large colonies, zooglea, through the 
medium of an albuminous excretion. Even under favorable conditions 
the germicide must penetrate the mass to effect sterilization. In addi- 
tion to this, the offending organisms may lie deep in a mass composed 
of fatty and albuminous matter, so that the question of the diffusibility 
of the antiseptic is an important one. 

" An antiseptic agent must be of sufficient strength to destroy the 
disturbing bacteria - 1 

" If bacteria develop so that the germicide can surround or easily 
penetrate them, they are more readily killed than when they develop 
in mass or clump-forms, and are surrounded by protective matter, as we 
find them in dental caries, root-canals, etc. In this state a stronger 
solution of the disinfectant is generally necessary, and a longer time will 
be required for the agent to penetrate the mass and act on the micro- 
organisms. 

" An agent should be employed that will not limit its own action and 
thus fail to reach all noxious germs. For instance, where the bacteria 
are imbedded in albuminous material, oxidizing agents, as hydrogen di- 
oxid, sodium dioxid, potassium salts, etc., will disintegrate and perme- 
ate the mass, while such agents as bichlorid of mercury and silver 
nitrate are apt to combine with the albuminous material and coagulate 
it, and thus limit or delay their own action. In this condition, the bi- 
chlorid may act as an antiseptic and restrain growth until the mercury 
is partly removed by the action of ammonium or hydrogen sulfid ; then 
the unkilled germs, or spores, will again develop if the nutrient material 
be favorable for their growth. Diluted solutions of such an agent, how- 
ever, are not apt to cause so dense a coagulum as to prevent permeation 
throughout the mass ; therefore a 1 : 1000 or 1 : 2000 solution of bi- 
chlorid of mecury is considered most desirable. The addition of 5 parts 
of tartaric acid to 1000 of the solution assists materially in preventing 
coagulation by bichlorid solutions (Laplace). 

" Germicidal agents that are incompatible should not be used together 
or one immediately after the other. Some agents become inert through 
chemical reaction when brought in contact with putrefying matter. 
Bichlorid of mercury, especially in dilute solutions, is rapidly decom- 
posed by sulfids, alkalies, ammonium salts, and even organic matter. 

1 These conditions and their connection have been well summarized by L. P. Bethel. 
in " Prize Essay " quoted. 



ANTISEPTICS. 533 

Therefore its use as a dressing for root-canals containing putrescing 
material is of doubtful value. 

" Very volatile antiseptics should not be used where a continued 
action is desired, as in root-canal treatment. 

" Fresh solutions should be used. Many preparations deteriorate 
with age, exposure, etc. 

" Again, the potency of germicides and antiseptics is increased by 
combining medicaments. For instance, the germicidal power of bichlorid 
of mercury is increased by the addition of hydrogen dioxid, benzoic 
acid, etc., and carbolic acid mixed with sulfuric acid increases its 
efficacy. When these and other disinfecting agents are combined with 
alcohol, glycerin, or oil, however, the germicidal power is greatly lessened. 

" Laboratory experiments show that bichlorid of mercury as strong 
as 1 : 250 solution in absolute alcohol, or 1 : 50 in glycerin, does not 
destroy well-exposed anthrax spores in two days' time ; but a 1 : 1000 
solution in alcohol plus 15 per cent, of water, or 1 : 500 in glycerin 
plus 50 per cent, of water, will destroy them in twenty-four hours. 

" Oil has about the same effect as glycerin. The results with carbolic 
acid, 1 : 10 solution, are similar. The advantage of using aqueous 
solutions when possible, is obvious. 

" Laboratory experiments show also that a warm or hot germicidal 
solution is more effective than a cold one. A 5 per cent, solution of 
carbolic acid at 70° F. requires one month to kill anthrax spores. Heated 
to 104° F. it kills them in about six hours ; at 135° F., in one hour 
and a quarter; at 180° F., in fifteen minutes. A 1 : 1000 bichlorid 
of mercury solution heated to 115° F. is equal in disinfecting power to 
a 1 : 500 solution used cold. Experiments made with various bacteria 
to determine why warm or hot solutions make this difference seem to 
indicate that not only is the vitality of the bacteria lowered, but the 
bacterial cell is actually enlarged or swollen, probably thus increasing 
the absorptive surface. 

" The thermal death-points, with moist heat, of some of the pus micro- 
organisms, are — bacillus pyocyaneus, 132° F. ; staphylococcus pyogenes 
aureus, 136° F. ; citreus, 143° F. ; albus, 143° F. ; cereus flavus, 134° 
F. ; cereus albus, 134° F. 

"This points out the advantage of using hot injections of water or 
disinfectant solutions in pyorrhoea alveolaris, pulpless teeth, antral and 
other diseases. 

" For germicides to act most effectively the field of operation should 
be as thoroughly prepared as possible previous to their application. 
For example, in root-canal treatment some instrumentation should 
precede the application of the dressing, to break up the compact masses 
and permit the germicide to penetrate to the organisms. 



534 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



" Grease should be removed by aqua ammonia?, equal parts of ether 
and alcohol, or chloroform ; and all other foreign substances, which 
might hinder the action of germicides used, should be removed." 

SALTS OF METALS AS ANTISEPTICS. 

The salts of metals are used in watery solutions as antiseptics — 
mercuric chlorid usually in 1 : 1000 solution ; zinc chlorid, 1 : 100 ; 
silver nitrate, 1 : 100; copper sulfate, 1 : 100. These are about the 
strengths in which these agents are found to act as efficient germicides ; 
but in the interiors of teeth, where the question of general poisoning 
rarely is a factor, and local poisoning only a remote possibility, these 
strengths may be greatly increased. 

Metallic salts act as germicides by chemically destroying protoplasm. 
When a metallic salt, in sufficient solution-strength, is brought in contact 
with albuminous material an obscure chemical change occurs, the metal 
entering into combination with the albumin and forming a substance 
which, for want of a better name, is called an albuminate of that metal, 
an opaque body replacing the transparent gelatinous albumin. For 
example, when mercuric chlorid is brought in contact with albuminous 
material, such as serous effusions, the serum of the blood, or living 
cells, animal or bacterial, the identity of the albuminous matter is 
destroyed. If a percentage of an organic acid, say tartaric (Laplace), 
be added to the mercuric solution before it is brought in contact with 
the albuminous matter, the above reaction does not appear to occur. 
The albuminate of mercury thus formed is decomposed under suitable 
conditions. If ammonium sulfid be added to an albuminate of mercury, 
mercuric sulfid is formed and the albumin is set free. This reaction is 
of importance as regards the use of mercuric chlorid as a disinfectant 
where sulfur compounds are present, as in putrefactive fermentation, 
when hydrogen sulfid is formed, a similar reaction may occur, and anti- 
septic effects be neutralized. During the putrefactive decomposition of 
albumin other substances than H 2 S, capable of decomposing mercuric 
chlorid, are formed. 

Mercuric chlorid inhibits the vital activity of living cells, even 
in very dilute solutions. A solution of 1 : 20,000 checks the move- 
ments of spermatozoa ; in one of 1 : 2000 it acts as a germicide to most 
micro-organisms, although several forms which have a resistive cell- 
wall delay the germicidal action. The spores of some species of bacilli, 
notably those of the bacillus anthracis, are markedly resistant. The 
precipitate of mercury albuminate which occurs interferes with the 
germicidal action of the solution ; the addition of tartaric acid to the 
mercury solution aids its germicidal property by preventing the forma- 
tion of mercurv albuminate. 



ANTISEPTICS. 535 

While all of the metallic salts named form with solutions of albu- 
min coagula, or albuminates of the metals, they differ in the rapidity of 
the chemical change and in the character of the coagulum. 1 " Capillary 
tubes containing a mixture of albumin and 20 per cent, of glycerin, the 
glycerin being added to prevent the drying of the albumin. One end 
of the tube was sealed, and saturated solutions of antiseptics applied at 
the other end for a period of ten days. Contrary to the belief generally 
held, silver nitrate was found to effect deep coagulation, the coagulum 
becoming dark in color ; zinc chlorid produced complete white coagula." 

These facts are of great importance, since they prove that the agents 
named, instead of being self-limited in action, may by prolonged con- 
tact affect deeper structures. 

Being a chemical reaction, there is, of course, as pointed out by 
Kirk, 2 a quantitative relationship between the substance acting and the 
substance acted upon. 

The presence of a coagulum of albumin between parts to be acted 
upon and the germicide must delay and interfere with the free diffusion 
of the germicide, as taught by Harlan ; but if the germicide be present in 
sufficient amount, it will diffuse through the coagulum, as demonstrated 
by the experiments of Kirk and Truman. 

Secondary changes have been noted in the coagulum with mercury. 
The coagulum of zinc chlorid is very resistant and appears to possess 
permanent antiseptic properties. The coagulum of silver nitrate under- 
goes chemical changes : the albuminate of silver is reduced to an oxid, 
and, if brought in contact with acids, forms corresponding salts of silver. 
For example, in contact with lactic acid silver lactate, a persistent 
antiseptic, is formed. 

These agents, used in sufficient strength, form coagula with the 
protoplasm of cells, coagulating intercellular albuminous material and 
forming an eschar — i. e., they are caustics. 

ALCOHOLS AND THEIR DERIVATIVES AS ANTISEPTICS. 

The alcohols and their derivatives also act as germicides by effecting 
coagulation of albuminous bodies. They differ in the rapidity of their 
action and in their germicidal strength. The cresols, trikresol having 
the greatest antiseptic power, carbolic acid next, and ethylic alcohol 
least, Formaldehyd in watery solution is the most promptly acting and 
penetrating agent of this group. 

HALOGEN DERIVATIVES AS ANTISEPTICS. 

The halogen group has its activity represented by the chemical affinities 
of iodin and chlorin. These agents abstract hydrogen from organic com- 
1 Truman, Proc. Academy of Stomatology, 1894. 2 Dental Cosmos, 1893. 



536 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



pounds, and thus destroy their identity. While it is certain that they act 
as germicides, destroying the vitality of protoplasm, their principal field 
of usefulness is in rendering innocuous the products of bacterial de- 
composition. The iodin derivatives named under this head are supposed 
to set iodin free when brought in contact with infected tissue, the iodin 
acting as a persistent disinfectant. Their activity is gauged, therefore, 
by the amount of iodin set free — i. e., by the amount present and the 
looseness of its combination. 

ACIDS AS ANTISEPTICS. 

The mineral acids effect the chemical destruction of animal sub- 
stances, inorganic and organic, with which they are brought in contact. 
They differ in their activity in this direction and in the depth of their 
action. For example, sulfuric acid quickly forms a black eschar upon 
tissue, chromic acid penetrates deeply into tissues to which it is applied. 
The milder acids, such as boric acid, appear to have no escharotic action. 

The strong mineral acids abstract the potassium, sodium, and cal- 
cium elements from tissues with which they are brought in contact, in 
addition to destroying albumin. The organic acids have a similar 
action. 

Solutions of hyposulfites act by virtue of the sulfite radical, S0 2 , 
which abstracts the elements of water from organic matter, forming 
sulfurous acid, H 2 SO s . The sulfite radical formed by burning sulfur 
acts in the same manner. 



CAUSTIC ALKALIES AS ANTISEPTICS. 

The caustic alkalies chemically destroy albuminous matters with 
which they are brought in contact. They combine with the fatty acids 
produced during putrefactive decomposition of tissues, and form soaps. 
The hydrates of sodium and potassium are the most active. These 
substances are formed when the alloy of sodium and potassium is brought 
in contact with organic matter. The alloy abstracts hydroxyl, HO, 
from organic matter, and produces secondary decompositions by the 
hydroxids of the metals which are formed. Sodium dioxid (Na 2 2 ), 
in contact with organic matter, sets free its loosely held oxygen atom, 
and the sodium ox id left quickly abstracts water from the organic 
matter, forming sodium hydroxid : 



NaA 



organic matter 



Xa 2 



HX> 



N 2 + 0+. 
2NaHO, 



which acts as above described. 

Aq. ammonise fort, acts by virtue of its affinity for water and fatty 
acids. 



ANESTHETICS. 537 

THE ESSENTIAL OILS AS ANTISEPTICS. 

The essential oils possess in varying degree the property of destroy- 
ing bacteria ; while it is probable that they effect a change in albuminous 
substances akin to coagulation, it has not yet been clearly demonstrated. 
Certainly they act as poisons when brought in contact with protoplasmic 
substances. Their germicidal power varies, that of the oils of thyme 
and cinnamon being greatest ; that of cloves (eugenol also) is less 
marked. Placed in the roots of pulpless teeth, they diffuse very 
gradually through the contents of the dentinal tubules. They may 
cause distinct staining of the tooth, a proof of their diffusion. 

PHYSICAL AGENCIES AS ANTISEPTICS. 

Of the physical agencies, the only available germicide is heat. It 
produces coagulation of albuminous matter, and is thus antiseptic. 
The degrees and conditions of heat necessary to complete germicidal 
action vary as to the mode of applying the heat and also upon the 
nature of the organisms present. Moist heat is a much more effective 
germicide than is dry heat. 

A degree of heat fatal to any mature organism may not destroy the 
vitality of its spores. The spores of some bacilli resist a temperature 
of boiling water for several hours. Most organisms, however, are 
promptly killed by water at a temperature of 212° F. 

Anaesthetics. 

An anaesthetic is any agent which prevents the perception of pain. 
A condition of insensibility to pain, or tactile sensitivity, may be 
induced in three ways : first, by paralyzing or destroying the terminals 
of sensory nerves through which impressions of pain are conducted — 
that is, by abolishing reception ; secondly, by interfering with or pre- 
venting the transmission of such impressions after their reception ; 
thirdly, by so acting upon the perceptive centre of the brain that its 
function is held in abeyance — i. e., by abolishing perception. 

Agents which have the power of lessening the consciousness of pain 
are grouped under the heads of anodynes, analgesics, and obtundents. 
The term anaesthesia, as originally used, indicated a condition of insensi- 
bility attended by loss of consciousness ; hence the term anaesthetic is 
usually employed to designate such substances as derivatives of ethane, 
notably ethylic oxid or ether ; derivatives of methane, such as methyl 
trichlorid or chloroform ; and nitrous oxid gas. 

An anodyne is an agent acting upon the pain-perceptive centre 
of the brain in such a manner that perception of pain is benumbed 
or lost ; the term refers to abolishing existing pain, as by the action of 
opium derivatives. 



538 DENTAL PHARMACOLOGY AND MATERIA MEDICA. 

An analgesic is an agent which either prevents or subdues pain, and 
may act upon any portion of the sensory tract. 

Under the head of obtundents are included those agents which are 
applied locally to benumb the terminals of sensory nerves. 

Hypnotics act as analgesics by inducing sleep, during which common 
sensation is in abeyance. 

The typical general anaesthetics are those named above ; chloroform 
as the representative methane derivative ; ether, the ethane deriva- 
tive ; and nitrous oxid, the asphyxial anaesthetic. 

Chloroform and ether act as general anaesthetics by abolishing the 
functions of the centres of consciousness in the cerebrum, and that of 
pain-perception. " They probably enter into loose combination with 
the protoplasm of the cortex of the brain, producing a temporary fixa- 
tion, and interfere with the process of oxidation and reduction upon 
which the functions of these cells depend." l 

The effects of these agents are progressive : the higher cerebral func- 
tions are first abolished ; next the special sense-perceptions ; then reflex 
activities ; until, finally, the centres which preside over the vital func- 
tions of respiration and circulation are involved, and if administration 
be carried beyond this point, death results. 

In general terms, these anaesthetic agents and their kindred may be 
said to be dangerous to life in proportion to their vapor-density. The 
greater their vapor-density, the longer they remain in the body. 

Nitrous oxid, under the usual conditions of administration, induces 
general anaesthesia by the exclusion of oxygen from the lungs and the 
accumulation of carbon dioxid in the blood ; in addition, it has a 
specific anaesthetic action, as unconsciousness and anaesthesia are in- 
duced when the nitrous oxid administered is mixed with oxygen. 
Nitrous oxid is to be regarded as the only entirely safe general 
anaesthetic. 

The number of fatalities attending the use of chloroform, the list being 
particularly large in connection with its administration for tooth-extrac- 
tion, is sufficiently extensive to absolutely contraindicate its use in that 
connection. The danger is twofold : first, the erect posture, which 
favors and appears to precipitate syncope ; secondly, the partial anaesthe- 
sia. More deaths are recorded as occurring in connection with partial 
than with full chloroform -narcosis ; probably under partial anaesthesia 
the reflexes are not entirely lost, and a condition of profound shock 
ensues upon performing minor operations. 2 Death under chloroform in 
some cases is due to paralysis of respiration ; in others, of the circulation. 
In many of the cases, when respiration ceases and the heart continues 

1 Lauder Brunton, Croonian Lectures, 1888. 

2 See Brunton, Pharmacology and Therapeutics. 



ANESTHETICS. 539 

to beat, life may be preserved if artificial respiration be maintained long 
enough for the body to rid itself of the chloroform-vapor. 

Representative anodynes, agents benumbing the pain-perception 
centre of the brain, are morphia and several of the coal-tar derivatives. 
These agents probably act in a manner similar to that noted in connec- 
tijon with the general anaesthetics, by forming loose combinations with 
the protoplasm of nerve-cells. Many of them affect the nervous paths, 
and when locally applied to sensory nerve-terminals reduce their func- 
tion, so that they may act as analgesics under all three heads named. 

The coal-tar derivatives are chemically the analogues of the vegetable 
alkaloids ; that is, they are substitution-products of ammonia. By re- 
placement of the several hydrogen atoms of the ammonia base pre- 
determined properties may be conferred upon compounds. Begin- 
ning with replacement by a phenyl radical and adding, for example, 
the anaesthetic basis methyl, analgesic substances are produced. For 
example, 1 NH 3 , ammonia, may have two of its hydrogen atoms replaced 
by other radicals : 

/C 6 H 6 
N — H = anilin 

\H 

/C 6 H 5 
N — H = phenyl acetamide or acetanilid, an analgesic agent. 



\COCH 



The remaining hydrogen atom may be replaced by the anaesthetic 
radical CH 3 , methyl, increasing the analgesic power of the compound : 

/C 6 H 5 
N — COCH3 forming methyl acetanilid, or exalgin. 
\CH 3 

Displacements and replacements in such comparatively simple bodies 
may be made, changes of physiological properties following upon changes 
of chemical composition. 

These agents have the power of paralyzing the paths of pain-con- 
duction. 

Equally instructive observations may be noted in connection with 
local anaesthetics, those agents which possess the power of benumbing 
the terminals of sensory nerves. Excluding such agents as volatile 
hydrocarbons, rhigolene, ethyl and methyl chlorid, in which specific 
paralyzing action is masked by the intense cold produced by their 
application, and inducing analgesia, it will be seen that the best-known 

1 Brunton, Croonian Lectures, 1888. 



540 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



and most active local anaesthetics are all related to one another in chem- 
ical composition. These agents are atropia, homatropin, tropacocain, 



cocain, and eucain. 



Atropia is a compound of tropic acid with tropein, a tropate of tro- 
pein ; either of these substances alone possesses no analgesic power, but 
the combination is slightly analgesic. If, however, tropein be combined 
with benzoic, instead of tropic acid, benzoyl tropein is formed (hom- 
atropin), which possesses marked anaesthetic properties. 

The next member, tropacocain (benzoyl pseudo-tropein), bears a 
chemical relationship to the former, and has additional anaesthetic power. 

Cocain is chemically benzoyl methyl ecgonin ; when boiled it is split 
up into methylic alcohol, benzoic acid, and ecgonin. The anaesthetic 
properties reside in the benzoyl methyl, and are much more marked 
than in compounds in which the methyl radical is absent. 

In eucain, the next member, benzoyl and methyl are both present, 
the latter multiplied and in several combinations, so that the anaesthetic 
properties are greater than those of cocain. 

If ethyl instead of methyl be combined with benzoyl ecgonin, an 
anaesthetic, cocethvlen, is formed. 

The benzoyl derivatives of other substances, such as morphia, have 
anaesthetic properties. 

The induction of analgesia by some local anaesthetics is preceded by 
a stage of irritation. 

The phenyls are all local anaesthetics, but many of them combine 
actively with the albuminous portions of tissues and act also as caustics. 

The benzoyl derivatives mentioned act not only as paralyzants of 
nerve-terminals, but, if applied or injected about the trunk of a nerve, 
induced analgesia in the distribution of that nerve. They paralyze 
nerve-centres to which they are applied. 

The essential oils possess the power of paralyzing sensory nerve- 
terminals, inducing, first, marked irritation ; this effect is absent when 
they are applied to the dental pulp, a tissue in which tactile sensitivity 
is normally absent. 

Astringents. 

Astringents are chemical agents which, when applied to swollen vital 
tissues, cause their contraction without their destruction. Many of 
them, however, if used in sufficient strength, immediately destroy the 
vitality of tissues to which they are applied ; for example, zinc chlorid 
in saturated solution is a powerful caustic ; in 10 per cent, solution is 
an active astringent ; and in 1 per cent, solution acts as a stimulant. 
The reason for this is readily seen from a study of its mode of action. 

Astringents are divided into vegetable and mineral ; the vegetable 



ASTRINGENTS. 541 

astringents owe their property to the tannic acid contained in them. 
The mineral astringents are mainly salts of iron, copper, lead, and 
zinc — acetates, sulfates, and chlorids. Astringents, with but few ex- 
ceptions, act by causing more or less coagulation of albuminous fluids 
and a shrinkage of the tissues in which they are contained, and, with 
the exception of subacetate of lead and nitrate of silver, do not cause 
contraction of bloodvessels ; tannic and gallic acids cause dilatation of 
vessels. 1 It will be seen, therefore, that, with the exception of silver 
nitrate and lead acetate, all astringents are positively contraindicated in 
active inflammation. Their sphere of usefulness is limited to states 
of venous congestion with effusion ; for example, in such conditions as 
chronically tumid gums, the use of an active vegetable astringent will 
cause constringing of the swollen tissues and dilatation of the arteries, 
with an increased flow of blood ; the weakened veins will receive sup- 
port, and stagnation be relieved. 

These substances differ in effect in proportion to their affinity for 
albumin, and the strength in which they should be used will depend 
upon this affinity ; for example, zinc chlorid or silver nitrate used in 
strength greater than 20 per cent, will combine with protoplasm and 
cause tissue-death. 

In combining two or more remedies regard should be paid to the 
chemical reactions which may occur between them and alter their 
nature ; drugs which, mixed together, produce undesirable combinations 
are termed incompatibles. It may easily happen in the practice of den- 
tistry that such mixtures may be made and produce ill-results ; for 
example, if sulfuric acid be used in connection with steel instruments in 
dental canals, and preparations containing tannic acid be afterward 
applied, a black tannate of iron forms, staining the dentin ; or, again, if 
attempts be made to bleach discolored dentin with nascent chlorin in 
teeth containing gold fillings, auric chlorid may form and cause per- 
manent staining. The following list from Hare 2 is a useful summary 
of common incompatibles : 

First. An acid should never be combined with an alkali. 

Second. An acid should not be added in any quantity to a tincture. 

Third. Alkalies should not be combined with the alkaloids. 

Fourth. Potassium chlorate should not be ordered to be rubbed up 
with tannic acid or any other organic substance capable of oxidation, as 
it will explode. Permanganate of potassium is subject to the same rule. 

Sixth. Iron is incompatible with tannic acid, as it forms a tannate 
of iron, or ink. As all the vegetable astringents contain tannic acid, 
none of them should be used with iron, except chiretta and calumba. 

Seventh. Tannic acid should never be added to solutions of alkaloids. 

1 Brunton, Pharmacology and Therapeutics. 2 Practical Therapeutics. 



542 DENTAL PHARMACOLOGY AND MATERIA MEDIC A. 

Eighth. Alcoholic solutions of camphor and similar resinous sub- 
stances are incompatible with water. 

Ninth. Fluid extracts are incompatible w T ith water, as the addition 
of water will cause a precipitate. 

Tenth. All salts not acid, but alkaline in reaction, are decomposed 
by acids. 

Eleventh. All salts which are acid are decomposed by alkalies. 

Twelfth. All vegetable acid salts are altered by mineral acids and 
are decomposed by alkalies. 

Thirteenth. Iodin and iodids should not be given with alkaloids. 

Fourteenth. Corrosive sublimate, the salts of lead, iodid of potas- 
sium, and nitrate of silver should always be prescribed alone. 

Fifteenth. Cocain and borax when added together form an insoluble 
borate of cocain. Boric acid and cocain do not form this substance. 

Electricity in Dental Therapeutics. 

Electricity is utilized in dental therapeusis for its physical, chemical, 
and physiological effects. For physical and chemical effects the con- 
stant or galvanic current alone is employed ; for physiological effects 
both interrupted (faraclic) and constant (galvanic) currents are applied ; 
the former rarely, the latter frequently. 

Physical Effects. — The physical properties utilized are the correla- 
tion of electric currents into light and heat. Small lamps operated at an 
electric pressure of 8 to 10 volts, placed in proper relation to reflecting- 
mirrors, are used to transilluminate teeth, to determine the vitality of 
their pulps. A somewhat less voltage is used in connection with an 
appropriate hand-piece and a loop of fine platinum wire to generate a 
high degree of heat in the latter — an electrocautery. This is used to 
destroy the peripheral portions of the dentinal processes in cases of 
excessive hypersensitivity of dentin. 

" If a long copper point be placed in a pulp-canal, and the electro- 
cautery be brought in contact with its end, sufficient heat is transmitted 
through the copper to dry the walls of the canal. If the canal be filled 
with an antiseptic oil prior to inserting the copper point, the oil may 
be vaporized and driven into the tubules. If wax or paraffin be placed 
in the canal, the copper point set in position, and heat applied, the 
substance will be melted and will run into all the interstices of the 
canal. The metallic point is permitted to remain as the central canal- 
filling." 1 

Physiological Effects. — An induced interrupted current was used 
by Bon will as early as 1859 to paralyze the reaction of the nerves 
about the root of a tooth, so that the latter could be extracted pain- 

1 Gramm, Dental Cosmos, vol. 35. 



ELECTRICITY IN DENTAL THERAPEUTICS. 543 

lessly. The same device has been used to allay the irritability of the 
dentinal processes and permit painless cutting of dentin. 

Rapidly interrupted currents have been applied to relieve the symp- 
toms of pulpitis and acute pericementitis. 

A moistened electrode applied to the back of the neck, the other 
pole upon the cheek, will tend to cause contraction of the blood- 
vessels. 

They appear to reduce also the pain referred to the seat of disease. 
The effects, however, are much less marked than when a galvanic cur- 
rent is employed. The latter is useful in those cases of trifacial 
neuralgia in which there is an irregular contraction of arteries. The 
galvanic current, 30-50 elements, will bring about a uniform contrac- 
tion of the vessels. This measure is merely palliative, not curative, so 
that in cases of reflex neuralgia of dental origin it precedes and follows 
removal of the cause. 

Chemical Effects. — The electrolytic power of the galvanic current 
is utilized in dental therapeutics. If a current such as is obtainable 
from the cataphoretic apparatus, with a maximum voltage of 35 to 40, 
be passed through vital tissues, 1 the electro-positive elements of the 
tissues, potassium, sodium, calcium, and hydrogen, appear at the nega- 
tive pole, and acids, chlorin, and oxygen at the positive pole. " It 
follows that if the positive electrode be composed of metal, it will be 
corroded by the action of the chlorin and acids, and the negative will 
remain unacted upon and smooth/' If the electrode be of zinc or of 
copper, the oxychlorids of those metals are formed, and exercise their 
chemical effects upon organic matter with which they are brought in 
contact ; hence they act as germicides and caustics. At the negative 
pole the caustic alkalies form and destroy tissue, if the application be 
sufficiently prolonged. The effects may be graded according to the 
current-intensity and duration of the application. Effective electrolysis 
is excited with 45 milliamp&res of current. 2 

If the negative pole be applied to the gum over a tooth, and the 
positive pole to the back of the neck and its position shifted from time 
to time, alkalies may be liberated in the tissues and cause effects ranging 
from effective counter-irritation to the actual breaking-down of indurated 
tissue, or the removal of hyperplasia. 

If the positive pole be placed in a root-canal and the negative pole 
upon some other point, fluids of the tooth or tissues about the apex of 
the root (if the electrode be carried into them) are decomposed, and 
the substances formed act upon the tissues. If a zinc electrode 
be used, the germicidal and caustic zinc oxychlorid is formed, as above 
noted. 

1 Bartholow's Medical Electricity. 2 Ibid. 



544 DENTAL PHARMACOLOGY AND MATERIA MEDICA. 

Another important property of the constant current is utilized in den- 
tal therapeutics, viz., the power of such a current to cause the passage 
through an intervening resistance, of substances in solution from the posi- 
tive toward the negative pole — cataphoresis, or electrical osmosis. This 
property is well illustrated by an experiment of Morton's. A glass 
vessel containing a porous septum dividing it into two chambers, has 
placed in one of the chambers a solution of starch, in the other a solu- 
tion of iodin. If now the positive pole of a galvanic combination be 
placed in the iodin solution, and the negative in the starch solution, the 
iodin is caused to pass more quickly through the septum, and the blue 
coloration of the iodin reaction with starch at once appears. 

Through the aid of such a current, with appropriate electrodes and 
under proper insulation, solutions of drugs may be caused to pass along 
the conducting paths of the dentin — L e., through their tubuli ; medica- 
ments may be carried from the surface of the gum into the pericemen- 
tum, etc. This principle is utilized in the treatment of hypersensitive 
dentin, for which special apparatus is necessary, so that the voltage may 
be raised by small fractions, the dental pulp being peculiarly intolerant 
of electric currents abruptly applied. 

Bleaching-agents, hydrogen dioxid solutions, may be quickly driven 
into the deeper portions of discolored dentin by this means. 

With suitable electrodes, cocain solutions may be driven in about the 
roots of teeth to render the operation of tooth-extraction painless. 

Hypodermatic Medication. 

Local anaesthetics — cocain, eucain, and tropacocain — are used by the 
hypodermatic method to render painless the operation of tooth-extrac- 
tion. Certain precautions should be observed in their use. The field 
of operation should be sterilized to prevent the entrance of pathogenic 
organisms to deep parts. The syringe and all of its parts must be care- 
fully sterilized, as must also the solution employed. Cocain solutions 
require the addition of an antiseptic. Eucain solutions may be sterilized 
by boiling. The minimum physiological dose of the drug should be 
employed, suspended in a large volume of fluid. The injection should 
be made in, not under, the maxillary periosteum. Injections should 
never be made in the loose tissue of the corium, as annoying swellings 
result and anaesthesia fails. 



ACETAN1LID— ACIDS. 545 



DENTAL PHARMACOPOEIA. 

The agents used in dental therapeutics and their modes of action 
have been considered under the head of dental pharmacology, so that 
further classification is unnecessary. The therapeutic application of 
any agent may be determined by noting its description under the 
alphabetical headings of this section, and then turning to the portion 
on pharmacology where general and specific group-properties are dis- 
cussed. 

ACETANILID (ANTIFEBRIN). 

Its name, acetanilid or phenyl acetamide, is derived from its chemical 
composition, graphically represented in 

N-C 6 H 5 
\C 2 H s O. 

Acetanilid. 

It is an amide, a substitution-product of ammonia, one hydrogen atom 
of ammonia being replaced by phenol, and one by acetyl, or it may be 
regarded as anilin, 

N— H 

Anilin. 

in which a hydrogen atom is displaced by acetyl. It is a whitish crys- 
talline powder, slightly pungent, without odor ; sparingly soluble in 
water, and freely soluble in alcohol, ether, and chloroform. Combined 
with ammonium carbonate, the mixture is known as ammonol. Com- 
bined with caffein citrate and sodium bicarbonate, the preparation is 
called antikamnia. 

It relieves pain and reduces temperature, and in large doses depresses 
the action of the heart. The dose is from 3 to 15 grs. In combination 
with ammonium carbonate its depressing action on the heart is almost 
neutralized. Used in painful affections, in neuralgia, and to lessen the 
pains of pulpitis and pericementitis ; grs. v., repeated until 15 grs. are 
taken. It has been used locally as a mild antiseptic to raw surfaces, 
instead of the usual antiseptic powders. 

Acids, 
acid, acetic, HC 2 H 3 2 . 

The glacial anhydrous acid, C 2 H 4 2 , is used as a caustic. 

Acid, Trichloracetic. — The trichloracetic acid is the form in which 

35 



546 



DENTAL PHARMACOLOGY AND MATERIA MEDIC A. 



acetic acid is used in dentistry, the three hydrogen atoms of the radical 
being replaced by chlorin, HC 2 C1 3 2 . This is a colorless and very deli- 
quescent substance. It coagulates albumin promptly, hence it is caustic. 
It is used deliquesced as a caustic to destroy gum overhanging developing 
lower third molars, and to destroy vital remnants of pulps in the roots 
of teeth. Diluted, it is used as an astringent in pyorrhoea pockets and 
to soften the deposits of calculi. 

ACID, ARSENIOUS. 

The anhydrous arsenious acid, or arsenic trioxid, As 2 3 , a white 
crystalline powder, is insoluble in cold water, but partially soluble in 
an excess of boiling water, when arsenious acid, H 3 As0 3 , is formed, 
a feebly acid substance. It is soluble in hydrochloric acid and freely 
soluble in alkalies. 

Combined with a fresh magma of ferric hydrate, the soluble arsen- 
ites are converted into insoluble arsenite of iron. This fact is made 
use of to prevent the absorption of arsenic which has been taken into 
the stomach. Evacuation of the contents of the stomach should 
follow. 

Applied to tissues, arsenic causes violent inflammation, followed by 
profound degenerative changes ; the application is attended by much 
pain. The inflammation excited by its presence prevents the absorp- 
tion of any but a very minute amount. It is used in dentistry for the 
sole purpose of devitalizing the pulps of teeth. It is made into paste 
and applied to the pulp ; or cotton-fibre is rolled in the paste, dried, 
and small pieces of it applied. 



Ify. Acid, arsenosi, 

Cocain. hydrochloride or 
Morphinse acetat., 
Ol. cinnamomi, or 
Ol. caryophylii, 



da gr. x ; 



q. s. ft. paste. 



ACID, BENZOIC, C 6 H 5 C0 2 H. 

Benzoic acid is prepared by heating gum benzoin ; the acid sublimes 
in pearly white plates. Faintly soluble in water ; freely soluble in 
ether, chloroform, and strong alcohol. Locally applied it is slightly 
stimulant. It is markedly antiseptic and non-poisonous, hence is 
a valuable ingredient in mouth-washes. 

acid, boric, H 3 B0 3 , 

is slightly soluble in cold water ; soluble in strong alcohol and in 
glycerin. A non-toxic antiseptic ; it is useful as an ingredient in 



ACIDS. 547 

mouth-washes. Combined with sodium sulfite, to evolve sulfur dioxid, 
S0 2 , for bleaching purposes (see Sodium Sulfite). 

ACID, CARBOLIC. 

Phenylic alcohol, phenyl hydroxid, C 6 H 5 HO, when pure, is colorless 
and crystalline ; odor is distinctive. Becomes fluid at 95° F. The addi- 
tion of glycerin renders it fluid. It is soluble in a great excess of water, 
a 3 per cent, solution being-permanent. It is readily soluble in ether, 
chloroform, alcohol, glycerin, and the essential oils. It coagulates albu- 
minous matter, hence is caustic •; it acts as a germicide in virtue of the 
same property ; locally applied, it is an anaesthetic. Used in dentistry in 
full strength to obtund the hypersensitivity of dentin, to relieve the pain 
of pulpitis ; as an antiseptic in carious cavities, in putrescent pulps, in 
root-canals, and in septic pericementitis. Used as a caustic for canker 
sores, stomatitis ulcerosa. 

In 3 per cent, solution it is used as an irrigating antiseptic and to 
keep sterilized instruments in, prior to using them. 

ACID, CHROMIC, CrO s . 

Chromic anhydrid, when deliquesced or dissolved in water, becomes 
H 2 Cr0 4 , or chromic acid. A powerful caustic, rarely used in dentistry. 
lias been used as a dentinal obtundent, and as a caustic in sluggish ulcers. 
Its present uses in dentistry are in ^ of 1 per cent, solution as a harden- 
ing fluid for histological work, and in galvanic batteries. 

ACID, GALLIC, 

does not coagulate (see Tannic Acid), but causes contraction of 
bloodvessels, hence is not used as a styptic locally, but when the inter- 
nal administration of a haemostatic is indicated. Given in pill-form ; 
dose, grs. 2-20. 

ACID, HYDROCHLORIC, HC1. 

Rarely used in dentistry. Used to supply deficiency of HC1 in 
stomach and to check fermentative processes there. It rapidly decalci- 
fies the hard tissues of the teeth. 

ACID, LACTIC, C 3 H 6 3 . 

A syrupy liquid freely soluble in water. It is the acid of fermenta- 
tive origin which decalcifies the teeth in the progress of caries. It has 
the power of dissolving fibrinous exudates, and is used, therefore, to 
remove the false membrane in diphtheria. In 20-50 per cent, solution 
it is used to soften deposits of calculi in cases of pyorrhoea alveolaris, 
and as a stimulant astringent to the engorged soft tissues about the 
parts. 



548 



DENTAL PHARMACOLOGY AND MATERIA MEDIC A. 



ACID, NITRIC, HN0 3 . 

The strong acid is used as a caustic application to canker sores. Its 
application is productive of pain, so that carbolic acid is preferred for 
this purpose. Used to touch abraded spots of hypersensitive dentin 
upon the occlusal faces of the teeth. As decalcification results, such 
spots are to be excavated and filled. 

acid, oxalic, C 2 H 2 4 , 

should be plainly marked, as its crystals are readily mistaken for 
those of magnesium sulfate (Epsom salt). Used to liberate chlorin 
from calcium hypochlorite, in the process of bleaching discolored dentin 
(Truman). 

ACID, PHOSPHORIC. 

The ortho-acid, H 3 P0 4 , in solution, is the fluid ingredient of zinc- 
phosphate cements. 

ACID, SALICYLIC, HC 7 H 5 3 , 

is contained in oil of gautheria (wintergreen). It may be obtained 
from this source, or be made synthetically by decomposing sodium 
salicylate with hydrochloric acid. Is slightly soluble in cold, freely 
soluble in hot water. Soluble in alcohol. Borax in solution aids the 
solubility of salicylic acid, hence their conjoined use in mouth- washes. 
In solution strength of 1 : 200, salicylic acid destroys most of the forms 
of bacteria found in the mouth. Its principal use in dentistry is as an 
ingredient of mouth-washes. 

ACID, SULFURIC, H 2 S0 4 . 

Sulfuric acid is used in dental therapeutics in 50 per cent, solution, 
mainly to gain access to, to enlarge, and sterilize root-canals so minute as 
to refuse entrance to fine instruments. It is used full strength as a destruc- 
tive obtundent in cases of hypersensitive dentin. In Aveak solution, 10 
per cent., it is used to neutralize the free alkali in teeth left after 
applications of sodium dioxid or sodium-potassium. The same solution 
is used to soften the deposits in cases of pyorrhoea alveolaris, to remove 
dead bone, and as an astringent. It is a solvent of the calcium salts of 
the teeth and destroys organic matter by a process of chemical dehy- 
dration. 

Acid, sulfuric, aromatic, is a mixture of sulfuric acid in alcohol, 
spirit of cinnamon, and tincture of ginger, in strength of 7-^ per cent. 
By the action of the sulfuric acid on alcohol a portion of the latter is 
oxidized, forming an ether. Its uses are those of dilute sulfuric acid, 
and, in addition, it has marked stimulating properties. It is used full 
strength in treating pyorrhoea pockets, as a calcic solvent, a germicide, 



ACONITE. 549 

a stimulant, and an astringent. It is used to dissolve carious bone and 
to stimulate the vital parts to reparative action. 

ACID, STTLFUROUS, H 2 S0 3 , 

acts as a bleaching-agent by a process of reduction, seizing upon the 
oxygen of the pigment. Is used as a bleaching-agent for discolored 
dentin. It is generated by mixing the dry powders of sodium sulfite 
and boracic acid, placed in contact with discolored dentin, water is 
applied and sulfurous acid is disengaged (Kirk). It acts as a deodorant 
and antiseptic in the same manner as above given. 

ACID, TANNIC, C 27 H 22 17 , 

is readily soluble in water, alcohol, and glycerin. It is the astrin- 
gent principle of most of the vegetable astringents. When oxidized, 
as when tannic acid is taken into the body, gallic acid is formed. It 
brings about a rapid coagulation of the blood with a contraction of 
vessel-walls ; hence is used as a styptic locally in powder. In solutions 
of various strengths adapted to the conditions, it is applied to reduce 
the passive congestion of swollen gums and tumid mucous membranes. 
Its solution in glycerin is known as glycerite of tannin ; it is made by 
dissolving 1 part of tannic acid in 4 parts of glycerin, through the aid 
of heat. This preparation is used in cases of swollen and passively 
congested mucous membranes ; the hygroscopic glycerin attracts the fluid 
exudates, and the tannic acid causes contraction of the engorged tissues. 
Tannic acid, in combination with alum, glycerin, and thymol, is used 
to mummify, and harden the remnants of pulps not removable by 
mechanical means. 

acid, trichloracetic. (See Acid, Acetic.) 

Aconite. 

Tincture of the root, tine, aconiti radicis ; dose 1 to 5 drops ; used in 
one-drop doses to reduce the pulsations of an overacting heart in acute 
inflammations. Locally used in combination with iodin to subdue peri- 
cemental inflammation : 

R. Tr. iodin., ] A/r 

Tr. aconiti rack, J 
Sig. Painted on gum, over the affected tooth. 

In old preparations the evaporation of the alcohol may, by concen- 
tration of the solution, increase the volume-strength, and poisoning may 
occur if used freely. Antidotes are cardiac stimulants — ammonia, 
whiskey, brandy. The physiological antidote is atropia. 



550 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



ACONITINE 

is the alkaloid of aconite, an extremely active poison, 
gr. Its dental use is in ointment : 



Its dose is 



1 

100 



]^. Aconitini, gr. j ; 

Cerat. simp., 3j. — M. 

Sig. To be rubbed over the tissues in front of the ear to relieve 
the trismus-like pains which may attend difficult eruption 
of lower third molars. 

Alcohol. 

Ethylic alcohol, C 2 H 5 HO, or ethyl hydroxid, 95 per cent, alcohol : 
being about 94 per cent, by volume, 91 per cent, by weight of ethyl 
hydroxid — i. e., 9 per cent, by weight, 6 per cent, by volume of water. 
Specific gravity at 60° F. 0.820. 

Methyl alcohol, CH 3 HO, methyl hydroxid. Whiskey and brandy 
containing from 48 to 56 per cent, by volume of ethyl alcohol, are used 
as diffusible stimulants in cases of syncope from any cause ; dose, 
oss-j. Strong alcohol is very astringent, and is antiseptic. Being 
hygroscopic, it readily takes up water ; this property is utilized in pro- 
ducing dryness of the dentin prior to inserting fillings and canal-fill- 
ings. Both ethyl and methyl alcohols are used as solvents for several 
vegetable gums which are employed in both laboratory and office uses. 
(See Lining Varnishes.) 

phenyl alcohol, C 6 H 5 HO, phenyl hydroxid. (See Carbolic 

Acid.) 

Alum. 

Aluminum potassium sulfate, A1 2 (S0 4 ) 3 ,K 2 S0 4 + 24H 2 0. 

Aluminum ammonium sulfate, A1 2 (S0 4 ) 3 ,(NH 4 ) 2 S0 4 + 24H 2 0. 

It is the potash -alum — aluminii et potassii sulfas — which is usually 
employed in medicine. It is a colorless salt, soluble in about fifteen vol- 
umes of cold water, and in three-quarters of a part of hot water. It has 
a sweetish, astringent, and acid taste, but unless the specimen contain 
free acid, alum solutions should be neutral in reaction. Alum-exsi- 
catum — dried alum — is alum whose water of crystallization has been 
driven off by heat, forming a white granular powder. 

Solutions of alum are used as astringent washes in cases of passive 
hyperemia of the gum-tissue, such as those caused by the presence of 
salivary calculi, and in pyorrhoea alveolaris. It should be ascertained 
that the alum contains no excess of acid — that is, should not redden 
blue litmus paper — before it is used. Powdered alum is a powerful 



AMMONIUM— ANTIPYRIN. 551 

styptic, and may be used on cotton tampons for the relief of alveolar 
hemorrhage. Alum exsicatum is used as a mild caustic to exuberant 
granulations : it acts both as a caustic and astringent. 

Ammonium. 

Ammonium hydrate, NH 4 HO, and the neutral carbonate 
(NH 3 ) 2 C0 3 , are used in combination with oils of lemon, pimento, and 
lavender, in solution of alcohol and water as a diffusible stimulant, 
under the name of spiritus ammonia? aromaticus. Given in doses of 
gss— ij, it acts as a prompt cardiac stimulant. 

Ammonium nitrate, NH 4 N0 3 , is the salt from which the anaesthetic, 
nitrogen monoxid (nitrous oxid), is disengaged. 

NH 4 N0 3 + heat (350°-450° F.) - N 2 4 2H 2 0. 

Ammonol (see also Acetanilid) 

is a combination of acetanilid with ammonium carbonate ; the latter is 
added to neutralize the depressing eifect of acetanilid upon the heart. 
Dose, grs. v-x. Used in neuralgic conditions, hemicrania, tic dou- 
loureux, and to benumb the pains of pulpitis and acute pericementitis. 
It is frequently very effective in the latter affection. 

Amyl Nitrite, Amyl Nitris, C 5 H n N0 2 

Dose, Tfl.ij--v. It is dispensed in glass pearls containing these amounts. 
It is administered by inhalation. It depresses the inhibitory apparatus 
of the heart ; used when the peripheral bloodvessels are in a state of 
marked contraction, it causes their immediate dilatation ; hence is used 
in angina pectoris, to relieve the spasmodic contraction of the heart and 
vessels, and in conditions of shock with pale surface. It has been 
suggested as an antidote to chloroform, when the conditions named 
present, but as it is also the antagonist of strychnia, the antidote of 
chloroform, its use must be guarded. 

Antipyrin 

is phenyl-dimethyl-pyrazolon. Irrespective of physiological experi- 
ments, a substance having the chemical composition given would, at the 
present day, be known to have the power of reducing pain and lessening 
temperature, which are in fact its uses. Dose, iii.-x grs. Antipyrin is 
freely soluble in water. Small doses decrease, large doses increase, the 
reflex activity of the brain, 1 the cause of the depression being due 
to sedation of the sensory nerves and of their centres in the spinal cord. 
Applied to mucous membranes or beneath the skin, this agent is a power- 

1 Hare, Practical Therapeutics. 



552 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



fal local anaesthetic, the anaesthesia lasting often for several days. Bar- 
tholow l and Hare both agree that the cardiac depressing action of anti- 
pyrin is over-rated, being only marked in the cumulative action of the 
drug. Its antidotes are atropia and stimulants. It is used to relieve 
the pain of facial neuralgia, pericementitis, and acute pulp-diseases. 



Aristol, Dithymol — Di-iodid. 

Introduced as a substitute for iodoform, upon the assumption that 
iodoform acts as an antiseptic in virtue of setting free iodin when brought 
in contact with vital tissues ; aristol containing twice the amount of 
iodin, should have greater power ; the thymol should also exercise par- 
ticular antiseptic action. Reports as to its efficacy are contradictory. 
Upon cocci and bacilli aristol has less power than iodoform (Hare). 
It is used in dentistry as a dressing in pulp-canals which have con- 
tained putrescent pulps ; its value as a persistent antiseptic in these 
cases is masked, owing to the previous or simultaneous use of other 
antiseptics. 

Borax, Na 2 BA + 10H 2 0. Boric Acid. 

Impure borax is the common flux of the dental laboratory. In this 
state it sometimes contains borates of other metals than sodium, which 
may cause contamination of the noble metals (Hiorns). Pure borax is 
soluble in twelve parts of water. Saturated solutions are used as 
mouth-washes in conditions of stomatitis (aphthae) as an antiseptic. It 
is an ingredient of Dobell's solution, which is used as an antiseptic wash 
in catarrh of, and empysema of the antrum, and in stomatitis : 



]^. Sodii boratis, 

Sodii bicarbonatis, 
Acidi carbolici, 
Glycerni, 
Aquse purse, 
S. Used warm, as a spray. 



da f *j ; 

gr. xxx ; 

Oij.— M. 



Boric acid is a useful addition to antiseptic mouth-washes. Used 
dry, on aphthous sores, and in cases of cancrum oris, ulcerative stoma- 
titis, etc., it is an admirable antiseptic. An ointment : 

1^. Ac. boric, 3j ; 

Cerat. alb., 3J ; 

Paraffin, 3ij ; 

Ol. amyg. exp., f^ij. — M. 

1 Materia Medica and Therapeutics. 



BOROGLYCERIN— CALCIUM. 553 

is a useful application to chapped lips and in herpes labialis, and to 
prevent chapping of the hands. 

BOROGLYCERIN * 

is made by mixing 62 parts of boric acid with 92 parts of glycerin, in a 
tarred porcelain capsule, at a temperature of about 300° F. The acid 
is added to the glycerin gradually, stirring constantly ; when the mixture 
is reduced to 100 parts it is poured on a block slightly wet with petro- 
leum ; when dry it is cut in blocks and kept in stoppered bottles. One 
ounce of these blocks is added to one ounce of glycerin to form glycerite 
of boroglycerin, a vehicle for carbolic acid and other substances applied 
as mouth-washes. 

Bromids. 

Potassium bromid, gr. v-3j. 

Sodium bromid, gr. v-^j. 

Used as sedatives when the cerebral circulation is overfull, as in 
teething children and in acute pericementitis. Applied locally to reduce 
the excessive irritability of the mucous membrane of the soft palate and 
fauces. Will relieve the form of migraine accompanied by flushed face 
and injected eye. Will quiet the irritability of hysterical dental patients. 

Caffein. 

Caffein, the active principle of coifee ; thein, the active principle of 
tea, and that of guarana, are chemically identical. Used in combination 
with acetanilid in the mixture called antikamnia (which see) to counter- 
act its depressing and increase its analgesic effects. 

Oajuput Oil. (See Oils, Antiseptic.) 
Calcium. 

Calcium oxid (lime) in solution in water has been used as an antacid 
mouth-wash. 

Calcium carbonate (precipitated chalk) is used as an ingredient of 
dentifrices, and as an antacid, rubbed over the teeth at night, to neutral- 
ize the acids causing caries and erosion, and to lessen the hypersen- 
sitivity of dentin. 

Calcium hypochlorite in mixture with calcium chlorid, is used as a 
bleaching-agent for discolored dentin. Chlorin is liberated by the 
action of dilute organic acids. 2 

The hypophosphites, phosphates, and lacto-phosphates have been ad- 
ministered to increase the amount of calcium salts in dentin in which 

1 Hare, Practical Therapeutics. 2 Truman. 



554 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



these salts were supposed to be deficient ; it has never, however, been 
demonstrated that they have any effect in this direction. 
Calcium sulfate (gypsum) calcined, is plaster of Paris. 

Camphor. 

Camphor liniment (soap, camphor, oil of rosemary, alcohol, and 
water) is used with friction over the masseter muscle to relieve the tem- 
porary spasms caused by difficult eruption of lower third molars. 

Camphor spirits, a few drops in a glass of water, is used to lessen 
the irritability of the soft palate and fauces, to permit manipulation of 
those structures. 

AMPHO-PHENIQUE . 

A fluid substance formed by the combination of nearly equal parts 
of carbolic acid and gum camphor, said to be a definite chemical body 
having the formula C 8 H n O, the reaction presumably being 

C 10 H 16 O + C 6 H 5 HO = 2C 8 H u O. 

Camphor. Phenyl alcohol. 

It possesses the antiseptic and anaesthetic properties of carbolic acid, 
and, in addition the stimulant property of camphor. It does not pro- 
duce an eschar ; it is insoluble in water. Its uses are those of carbolic 
acid in general ; but it has not the depressing effect of that agent upon 
the vitality of tissues to which it is applied. It is used in full strength 
for hypersensitivity of dentin, to sterilize infected and purulent pulps, 
and as a stimulant antiseptic application to the walls of chronic alveolar 
abscesses. It may be used as a stimulating antiseptic application to 
pyorrhoea pockets after removal of the deposits and washing with 
hydrogen dioxid. 

Oantharides (Spanish Flies). 

An active principle called cantharidin, is extracted from the crushed 
bodies of the beetle, cantharis vesicatoria. It is used in plaster, charta 
cantharadis, or in collodion, collodion cum cantharide, to produce blis- 
tering. A blister placed in front of the ear or beneath the ear is a 
counter-irritant of service in relieving the pains of pulpitis and peri- 
cementitis, after local therapeusis has been applied. A small blister 
applied to the gum, at some distance from an affected root, is useful in 
cases of sluggish pericementitis of the chronic type. 

Capsicum. 

Depending upon the strength in which they are used, preparations 
of capsicum are stimulants or irritants, and are used to stimulate slug- 
gish local circulation or as counter-irritants. 



CHLORAL HYDRATE— COCAIN. 555 

Tr. capsicum may be used alone, or as tr. capsici et myrrhse ; either 
is added to water until cloudiness appears ; used as a stimulant wash in 
cases of atonic affections of the gum-tissues, and to hasten the separa- 
tion of sequestra of bone. Powdered capsicum and ginger, made into 
packet-form, in small muslin bags, and called capsicum bags, are useful 
as counter-irritants in acute pulp-affections and in chronic pericemental 
disturbances. 

Chloral Hydrate, C 2 HC1 3 0.H 2 0. 

The syrup of chloral, in doses of f3j, is an admirable hypnotic in 
cases of insomnia from pulpitis, and after arsenical applications have 
been made to a pulp. In saturated solution it has been used to reduce 
the hypersensitivity of dentin. Its solutions are markedly antiseptic and 
are irritant to soft tissues. 

Chloroform, Formyl Trichlorid, CHC1 3 . 

The most dangerous of the general anesthetics in dental practice ; it 
should never be used in dentistry for this purpose. The list of fatalities 
recorded from the employment of chloroform in tooth-extraction is a 
most formidable one. The semi-erect position adds to the danger 
always accompanying the use of this agent. It is used in dentistry as a 
counter-irritant. A piece of blotting-paper saturated with chloroform 
laid upon mucous membrane or skin, and its evaporation prevented by 
covering with rubber cloth, acts as a stimulant, counter-irritant, or vesi- 
cant, according to the length of application. It is used as a solvent for 
gutta-percha base-plate, to make the root-filling solution called chloro- 
percha. 

Cobalt. 

A powder named cobalt has been used to destroy the vitality of the 
dental pulp, particularly after the Herbst method. Analysis has shown 
this powder to be metallic arsenic or arsenic sulfid (Kirk). 

Cocain (Hydrochlorid), Benzoyl-methyl Ecgonin. 

Decomposed, by boiling, into methylic alcohol, benzoic acid, and 
ecgonin ; therefore, unlike eucain, its solutions cannot be sterilized by 
boiling. Solutions of cocain paralyze the terminals of both sensory and 
special sense-nerves with which they are brought in contact. Applied 
to nerve-trunks they prevent the transmission of sensory impressions. 
Death from overdose is due to paralysis of respiration. Poisoning 
should be treated with stimulants — ammonia, strychnia, or ether. 

It is used in dentistry in solutions of various strengths as a local 
anaesthetic. In from 4 to 10 per cent, solution as an application to the 



556 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



mucous membrane to render incision painless. In saturated solutions 
or in crystals, or in paste with glycerin, is used in acute diseases of the 
pulp as an analgesic. In solution with agents added to overcome ill— 
toward effects, and to prevent the growth of organisms which will 
develop in watery solutions of the drug, cocain is used as an agent 
for hypodermatic injection to render the operation of tooth-extraction 
painless. 



]^. Cocain. hydrochloride, 
Morphinse sulph., 
Atropinse sulph., 
Trinitrin (1 per cent, solution), 
Acid, carbolic, 
Aquae, 



g r - TT ; 
q. s. ft. 3ss. — M. 



The above is a full dose, making about one-half syringeful. The 
syringe-needle is passed deep into the connective tissue between mucous 
membrane and alveolar periosteum over a root, and several drops of the 
solution are injected. A similar injection is made upon the opposite 
side of the same root, or over other roots ; extraction should be done 
almost immediately. Prior to making the injection the mucous mem- 
brane at the point of injection should be carefully sterilized, as should 
also the syringe and needle. 

In strong solution, cocain is forced into the dentinal tubuli and into 
the dental pulp by means of the cataphoric current, to obtund hyper- 
sensitive dentin or to paralyze the pulp and permit its removal. Cocain 
without this driving force is ineffective as a dentinal analgesic, even in 
saturated solution or in glycerin paste. 

Collodion. 

A solution of pyroxylin (gun-cotton) in ether and alcohol. Exposed 
to the air, the solvent evaporates and leaves a thin, transparent, imper- 
meable film. Cantharidal collodion is formed by adding cantharides- 
extract to collodion. Styptic collodion is made by dissolving tannic 
acid in collodion : tannic acid, grs. 20 ; collodion, ^j. This makes a 
useful application to oozing, abraded surfaces after previously sterilizing 
them. Steresol (which see) varnish is, however, superior to it. 



Copper, Cuprum. 

Black cupric oxid combined with orthophosphoric acid forms a black 
cement, orthophosphate of copper, advised as a filling-cement in dentistry 
to underlie other materials. 1 Cupric sulfate — Milestone — according to 



Ames. 



COTTON— CRESOLS. 557 

the strength of solution in which it is used, is an astringent or caustic. 
Copper sulfate acts as a germicide, like the other metallic salts mentioned, 
by causing coagulation of albumin. 

Miller's 1 experiments demonstrated that crystals of cupric sulfate 
placed upon the surface of a pulp transformed the entire pulp into a 
green, antiseptic, tough mass. It causes, however, a green discoloration 
of the dentin, and if used when putrefactive decomposition is in progress, 
black copper sulfid is formed by the action of the hydrogen sulfid 
present. 

A crystal of cupric sulfate is a useful application to the dentin of 
deeply infected teeth which are to be enclosed by barrel crowns. In 
strong solution it is a useful agent in the cauterant treatment of pyor- 
rhoea pockets. In 1 per cent, solution it is a useful astringent and 
antiseptic wash for relaxed conditions of the soft tissues about the 

mouth. 

Cotton. 

The hairs of the seeds of the cotton-plant (gossypium herbaceum). 
In the carded state it is the raw cotton of dentistry. Boiled with a 
5 per cent, solution of sodium or potassium hydrate, fatty substances 
and foreign matters are washed away, and the boiled cotton is afterward 
washed with calcium hypochlorite ; this is absorbent cotton. Each fibre 
consists of elongated tubular cells, which absorb any moisture with 
which the cotton is brought in contact. The cotton should contain no 
free alkali or free acid. Mixed with arsenical paste and dried, it con- 
stitutes devitalizing fibre. 

Corrosive Sublimate. (See Mercuric Chlorid.) 

Creosote, 

A product of the distillation of wood, etc. ; it contains carbolic acid 
and allied substances ; its properties and uses are those of carbolic acid. 

Cresols, nominally C 6 H 4 CH 8 OH. 

methyl phenol. 

Obtained by fractional distillation of crude carbolic acid at 365°-401° 
F. There are three cresols, ortho-, meta-, and para-cresol, the second 
being the most powerful germicide. Para-cresol is a local analgesic, 
destroying the sense of pain, but not tactile sensibility. 2 It will be 
seen that the chemical composition of these substances shows them to 
be allied to cocain and carbolic acid. Frankel and Gruber found 
a mixture of the three cresols — called trikresol — to possess three times 
the disinfectant power of carbolic acid. Trikresol may be used with 
advantage to replace carbolic acid in dental practice. 

1 Dental Cosmos. 2 McNeill, Edinburgh Med. Jour., 1886. 



558 DENTAL PHARMACOLOGY AND MATERIA MED1CA. 

Ergot. 
The fluid extract in drachm doses is used as a haemostatic. 

Erigeron, Fleabane. 

The oil of erigeron, in doses of from twenty to thirty drops in 
capsules, is used in oozing alveolar hemorrhage after the extraction of 
teeth. 

Ether, Ethyl Oxid, (C 2 H 5 ) 2 0. 

Used as the major anaesthetic for dental operations, when it is essen- 
tial to keep the patient anaesthetized for comparatively long periods, as 
in the removal of imbedded, impacted teeth. Dividing the anaesthetic 
stages of ether into four, the first stage is when sensibility to pain is 
dulled before the loss of consciousness occurs ; teeth may be extracted 
in this period, or excessively hypersensitive dentin may be cut, without 

pain. 

Ethyl Chlorid, C 2 H 5 C1, 

is too volatile for use as a general anaesthetic. It boils at 12° C. It is 
used as a refrigerant local anaesthetic, its rapid evaporation causing 
quick paralysis of sensory nerve-terminals or trunks. A spray of this 
agent directed against vital dentin will benumb its sensitivity, and if 
the application be prolonged refrigeration extends to the pulp, which in 
many cases can be extracted painlessly. A spray directed upon the 
gum will freeze it and permit the extraction of a tooth without pain. 

Eucain Hydrochlorid, 

a synthetic substance, having a methyl-benzoyl basis, as in cocain ; its 
composition is, however, much more complex than that of the latter. 
Solutions in water may be boiled without decomposition ; hence, unlike 
cocain, solutions may be sterilized by boiling. It is not so toxic as 
cocain. It may be used in watery solutions which have been boiled, in 
amounts of -|— J gr. by hypodermatic injection, to render tooth-extraction 
painless. 

Exalgen, METHYL- ACETANILID, 

is acetanilid in which the remaining hydrogen atom of the basal 
ammonia is replaced by methyl : 

/H /CH 3 (methyl) 

N— COCH3 N— COCH3 

\C 6 H 5 \C 6 H 5 

Acetanilid Methyl acetanilid, or exalgin. 

Its analgesic power is greater than than of acetanilid. Its uses are 
the same in treating painful affections, but it is not used as an anti- 
pyretic. 



FORMALIN— HAMAMELIS. 559 

Formalin, 

a 40 per cent, solution of the gas formaldelyd (CH 2 0) in water. For- 
maldehyd is an oxidation-product of methyl alcohol. A powerful 
antiseptic ; in 1 : 1000 solution it prevents the growth of anthrax 
spores ; in 1 : 2000 solution it checks putrefaction in bouillon. 1 The 
vapor (powerfully antiseptic) is given off from formalin solutions at 
ordinary temperatures. It produces tough coagula when brought in 
contact with albuminous substances. Both vapors and solutions are 
very irritating. Any strength in excess of 5 per cent, placed in root- 
canals is productive of irritation ; and the dental pulp responds pain- 
fully to any solution of a strength above 3 per cent. 2 It is used in the 
indicated strength in connection with putrescent pulps, prior to attempts 
at mechanical manipulation, to penetrate and sterilize to the root-apex. 
In 1 per cent, solution it is an excellent injection for deep-seated 
abscesses, particularly those of a chronic type. In 1 per cent, solution 
in combination with other agents it is an admirable antiseptic mouth- 
wash. 

Glycerin, Propenyl Alcohol, C 3 H 5 (OH) 3 , 

is set free when natural fats are boiled in a caustic alkali. Stearates of 
potassium or sodium (soaps) are formed and glycerin is liberated. It 
has moderate antiseptic powers and is very hygroscopic. A drachm or 
two injected into the rectum produce a watery stool, and this fact is 
utilized in the derivatant treatment of teething-convulsions. Mixed 
with equal parts of water it is useful to relieve " dry mouth and fauces." 
In combination with tannic acid it forms glycerite of tannin (which see). 

GUAIACOL. 

A distillation-product of creasote, containing from 60 to 90 per cent, 
of that substance. Its uses are in general those of creasote. A 10 
per cent, solution of anhydrous cocain hydrochlorid in pure guaiacol is 
termed guaia-cocain, 3 and is used instead of watery solutions of cocain 
in connection with the cataphoric current to benumb hypersensitive 

dentin. 

Hamamelis. 

Fluid extract, dose internally 5-20 drops. The distilled extract 
(Pond's extract) may be used in doses of 3ss-3J internally. Internally 
it is used as a haemostatic to check oozing hemorrhage. Locally it is 
used to reduce vascular engorgement. It is an efficient antiphlogistic 
for use in inflammatory conditions of the mouth and fauces. Is very 
useful as a general mouth-wash in cases of pericementitis, after the excit- 

1 U. S. Marine Hospital Reports, July, 1897. 2 L. Jack. 

3 W. T. Morton. 



560 DENTAL PHARMACOLOGY AND MATERIA MEDIC A. 

ing causes of the inflammation have been removed. It is used as a wash 
in cases of gingivitis. 

Hydrogen Peroxid, Hydrogen Dioxid, H 2 2 . 

In 3 per cent, watery solution yielding ten volumes of oxygen. In 
5 per cent, ethereal solution. In 25 per cent, ethereal solution, caustic 
pyrozone. Sodium dioxid, from which hydrogen dioxid is disengaged 
by the action of dilute mineral acids. Most of the watery solutions of 
hydrogen dioxid are slightly acid in reaction. Solutions of hydrogen 
dioxid deteriorate with age, and very quickly upon open exposure. 
Their activity may be judged by the violence of the reaction which 
occurs when potassium permanganate is added to the solutions. Used 
as a germicide, antiseptic, and disinfectant; acting by virtue of the 
nascent oxygen set free when the solutions are brought in contact with 
organic matter. (See Antiseptics, Nascent Oxygen, and Caustic Alka- 
lies.) Used in abscess-cavities, pus-pockets, pulpless roots, pulp-dis- 
eases, and in all conditions where an active and non-toxic antiseptic is 
indicated. 

Iodin, Iodids. 

Tr. iodin and liq. iodi comp. (LugoPs solution). Tr. iodin evapor- 
ated to one-fourth its volume is called dental tincture of iodin. 1 Iodin 
is incompatible with mineral acids, metallic salts, and vegetable alka- 
loids. Iodin in vapor, solid, or in solutions, decomposes hydrogen 
sulphid and hydrogen phosphid, acting as a deodorant. It combines 
with albuminous substances, acting as a germicide. Locally applied, it acts 
as a stimulant, irritant, or caustic, depending upon the concentration of 
the solution. It is used as a counter-irritant in cases of pulpitis and 
pericementitis (acute), and to resolve indurations about the teeth due to 
chronic inflammation of the pericementum. Used in pulp-chambers 
to quickly deodorize the putrescent pulp. If the cavity be washed 
with ammonia-water, afterward any iodin-stain is removed and the 
dentin whitened. Used diluted in conditions of tumid gums, and as a 
stimulant application in deep pyorrhoea pockets. The liq. iodi comp. is 
preferable in such cases. 

Iodoform, Formyl Tri-iodid, CHI 3 . 

Iodoform, by virtue of its organic radical, is a local anaesthetic. It 
is antiseptic, although not a germicide. Its action in this direction is 
believed to be due to one of two causes : either by virtue of the iodin 
which is set free when iodoform is brought into contact with infected 
tissues, or to chemical changes which it induces in the poisonous prod- 

1 Flagg. 






IODOL—LYSOL. 561 

ucts of bacteria, rendering them non-toxic. The reduction of irrita- 
bility by the formyl radical must, in addition, play an important part in 
inducing regeneration of tissues over surfaces to which iodoform is 
applied. Used in conjunction with arsenic trioxid in devitalizing paste, 
it lessens the pain incidental to pulp-devitalization. 1 

1^. Acid, arsenosi, gr. v ; 

Iodoform i, gr. x ; 

01. cinnamomi, q. s . ft, paste. 

There is much discrepancy of opinion as to the value of iodoform, 
brought about by the observation that it is not a germicide ; nevertheless 
in pyogenic conditions of a chronic type it appears to have distinct 
value. It is used in solution or in powder in the cavities of chronic 
abscesses or pyorrhoea pockets. Gauze charged with iodoform, iodoform- 
gauze, is used to pack abscess-cavities which have been opened artifi- 
cially through the alveolar walls, and after root-amputations. Under its 
use regeneration and healing proceed more uniformly than with most 
medicinal applications. Iodoform is used freely in cases of tuberculosis 
of the jaws. 

Iodol, Tetra-iod-pyrrhol, CJ4NH. 

Introduced as a substitute for iodoform, it contains about the same 
volume of iodin in looser combination. It is inodorous. Applied to 
wounds iodin is set free and acts upon albuminous substances, from 
which ozone is disengaged, which oxidizes compounds of sulfur and phos- 
phorus. 2 Its uses are those of iodoform, except in arsenical pastes, 
where the anaesthetic property of iodoform is utilized. 

Iron. 

Freshly prepared hydrated sesquioxid of iron is the antidote to 
arsenic. Tr. ferri chlor. is occasionally used as a styptic in alveolar 
hemorrhage. MonselFs solution, sol. ferric subsulfate, is a powerful 
styptic, but may cause sloughing of tissues. Preparations of iron are 
rarely used in the mouth on account of the stains they produce upon the 
teeth. 

Kino, Krameria, 

vegetable astringents used in mouth-washes, acting by virtue of the 
tannic acid contained in them. 

Lysol 

is a carbolized compound, made by dissolving in fat and saponifying 
with alcohol that part of coal-tar which boils between 190° and 200° C. 

1 Truman. 2 Bartholow. 

36 



562 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



It forms a clear, soapy fluid with water. Is used in 2 to 4 per cent, 
solution to sterilize the washed hands, and in boiling solutions of the 
same strength to sterilize instruments. In full strength it is an excel- 
lent penetrating antiseptic as a first application to pulps in a state of 

partial putrescence. 

Magnesium. 

Magnesium hydrate in suspension is Phillip's milk of magnesia. 
It is perhaps the best of all antacids for use in dental therapeusis. 
It forms a film of magnesium hydrate upon the surfaces of the teeth 
and aids materially in checking the advance of dental erosion. 

Magnesium sulfate in doses of 3ss, well diluted, is an excellent 
derivative saline cathartic in cases of acute pericementitis. 

Menthol, Mint Camphor. 

The active principle of peppermit, upon which its effects depend. It 
is a local anaesthetic and produces contraction of the small vessels of the 
part to which it is applied. This combination of properties renders it 
very useful in treatment of acute pulpitis. Used dissolved in chloroform 
or oil of cassia, it is an excellent agent in the treatment of the peri- 
cemental irritation which occasionally follows upon the removal of the 
pulp. It is pumped in the canals and permitted to remain for a day or 
longer. A solution (gr. j-3) is a useful wash in cases of sluggish 

stomatitis. 

Mercury. 

Metallic mercury is used as the solvent of dental alloys. 

Mercury bichlorid, Hg-CL^, in strength of 1 .-2000 1 is found to act 
as an effective sterilizing agent in the human mouth, killing in a very 
few minutes, nearly all forms of bacteria found in that cavity. Its 
disagreeable taste and the danger of discoloring the dentin of the teeth 
contraindicate its use as a general oral antiseptic. In pulpless teeth, 
particularly in those in which the pulp has become gangrenous and un- 
dergone putrefactive decomposition, the use of mercuric chlorid is con- 
traindicated because of its reaction with the hydrogen sulfid generated 
during this type of fermentation. The danger of discoloring, salts 
of mercury being formed and finding their way into the dentinal tubuli, 
is an ever-present one. 2 

It has been found that tablets composed of mercury bichlorid and thy- 
mol in equal parts, when crushed in the base of a pulp-chamber against 
the stumps of pulps which have been intentionally devitalized, will main- 
tain a prolonged antiseptic condition in the roots of teeth so treated. 3 

1 Miller, Micro-organisms of the Human Mouth. 

2 Kirk's Operative Dentistry, chapter "Bleaching." 

3 Miller, Proc. Columbia Dental Congress. 



METHYL CHLORID— MORPHIA. 563 

Corrosive sublimate has found but limited clinical application in dental 
practice, it being possible to induce antisepsis with other germicides 
which have not the disadvantageous features of the mercury salt. It is 
not adapted for sterilizing metallic instruments on account of its corro- 
sive action upon steel, and the precipitation of mercury upon other 
metals. In hot 1 : 2000 solution it is an effective sterilizer for e*lass- 
ware used by the dentist. In 1 : 1000 solution it is an effective lavage 
in conditions of ulcerous stomatitis, although hydrogen dioxid followed 
by potassic chlorate has largely displaced it for this purpose. A 1 : 1000 
solution in hydrogen dioxid is an excellent germicidal application to 
abscess- walls. 1 

Mercury sulfid, HgS, vermilion, is the pink coloring-matter of 
gutta-percha base-plate. As this salt is insoluble in lactic acid, fillings 
made of pink gutta-percha do not acquire a rough surface like those 
made of preparations containing the soluble zinc oxicl. The red oxid 
of mercury is used as an ingredient for lip-salves to relieve cracks and 
abrasions about the lips : 

1^. Mercuric oxid., .*j ; 

Tr. benzoin, 3j ; 

Cerat. simp., ^ij ; 

Liq. potassii, gtt. ij. — M. et ft. ungent. 

(J. F. Flagg). 

Methyl Chlorid, Mono-chlor-methane, CH 3 C1, 

the lightest and most volatile of the compounds of chlorin with methane, 
the heaviest being chloroform, tri-chlor-methane, CHC1 3 . Methyl 
chlorid vaporizes at a temperature below zero ; hence it is the most 
active refrigerant available as a local anaesthetic. It possesses an addi- 
tional advantage over ethyl chlorid, in that it is but slightly inflam- 
mable. A spray of methyl chlorid directed against the gum for a frac- 
tion of a minute or longer will create sufficient local anaesthesia to 
render the operation of tooth-extraction painless. The application 
should not be continued too long, or tissue-death will result. A spray 
directed against hypersensitive dentin or an exposed pulp, will render 
both entirely anaesthetic. Vital pulps may be rapidly paralyzed through 
the application of a spray of methyl chlorid. The spray may be used 
as a cold test to determine the vitality of a pulp. 2 

Morphia. 

The anodyne alkaloid of opium. It possesses the power of benumb- 
ing the functions of the sensory nervous tract when internally admin- 

1 Khein. 2 Ibid. 



564 



DENTAL PHARMACOLOGY AND MATERIA MEDIC A. 






istered. Locally applied it is an obtundent to sensory nerve-terminals. 
The sulfate is the most effective salt for internal use ; the acetate for 
external application. Morphinse sulfate, gr. -J-, administered a half-hour 
before operating will in many cases so benumb sensitivity that the pain 
of cutting hypersensitive dentin is materially reduced. The same 
dose may be required as a general anodyne in conditions of pulpitis and 
acute pericementitis ; it has been largely displaced for such purposes 
by the coal-tar derivatives, which relieve pain without the unpleasant 
after-effects frequently following upon the use of morphia — i. e., con- 
stipation and headache. 

Acetate of morphia was the usual anodyne ingredient in arsenical 
paste-formula? ; it has been almost entirely superseded by cocain hydro- 
chlorid. 

Naphthalin, C 10 H 8 . 

The naphthalin derivatives are all analogues of carbolic acid. Resor- 
cin (which see) belongs also in this chemical and medicinal group. Car- 
bolic acid and resorcin belong in the group which has but a single ben- 
zene nucleus, C 6 H 6 : naphthalin in that having a double benzene nucleus. 
Phenylic alcohol is benzene in which one hydrogen atom is replaced by 
hydroxyl, C 6 H 5 HO. Resorcin has two of its hydrogen atoms so re- 
placed, C 6 H 4 (HO) 2 . 

Naphtol. 

The hydroxyl derivative of naphthalin has the composition C 10 H 7 HO. 
There are two naphtols, the alpha and the beta, both having the same 
formula — are isomeric. The latter is more soluble in hot water, and its 
leaflet-like crystals have lower melting- and boiling-points than the 
needle-like crystals of a-naphtol. Only /9-naphtol is used in surgery. 

Hydronaphtol, a proprietary agent, is said to be identical with /3- 
naphtol. 1 The penetrating and preserving qualities of this agent, how- 
ever, appear to be superior to those of /9-naphtol. 

Naphtol solutions are made in alcohol, these solutions being mis- 
cible in hot water. Miller's experiments indicate that these solutions 
are promptly germicidal, 2 but that they do not induce prolonged anti- 
sepsis. 3 

The chemical analogy of naphtol to carbolic acid is, of course, an 
indication of some or of a close degree of physiological properties. 

/9-naphtol or hydronaphtol in 1 : 300 solution is used as a spray 
for sterilizing pyorrhoea pockets, for sterilizing alveoli after extraction 
and prior to plantation operations. In 1 : 50 solution or stronger it is 
used in septic pulp-canals, and in the treatment of septic apical peri- 
cementitis. 

1 Gould, Illustrated Did. of Medicine. 2 Micro-organisms of the Human Mouth. 

3 Dental Cosmos, 1891. 



NITROUS OXID— OXYGEN. 565 

Nitrous Oxid, Nitrogen Monoxid, N 2 0. 

The only entirely safe general anaesthetic. Anaesthesia is induced in 
from one-half to two minutes, and ceases in from one to three minutes. 
Ill-effects from its use are rare ; those that have been noted were usu- 
ally in patients whose vessels were atheromatous. Patients having pul- 
monary emphysema, or fatty heart, may be distressed for hours after its 
administration, and its use in the three classes of disorders named can- 
not be regarded as without danger. 

Oils, Antiseptic. 

Several of the essential volatile oils are used in dental practice as 
antiseptics. In addition, most of them possess obtundent action upon 
the dental pulp. The several oils differ as to their activity in both of 
these directions. All of these oils belong to the aromatic series — i. e., 
they have a relationship to benzene. 

The oil of caryophyllum (cloves) contains an oxygenated oil. Eu- 
genol, having basic properties, is eugenic acid. The oils of cajuput, 
cassia, and cinnamon (cassia being the Chinese cinnamon, the Ceylon 
oil that of cinnamon proper), eucalyptus, gaultheria, myrtle, and thyme, 
all find useful application in dentistry. Of these, oil of white rgreen 
possesses the least antiseptic properties, oil of eucalyptus the least ob- 
tundent action ; the most powerful antiseptic action being in the oils of 
myrtle, cinnamon, and thyme, the last named being the most marked 
antiseptic and obtundent. It ow r es its efficiency to a stearopten, thymol 
(which see), contained in it. These oils may be applied freely to exposed 
and aching pulps, benumbing them quite promptly and apparently hav- 
ing no deleterious action upon their vitality. 

Oil of cinnamon is a persistent, and powerful, slowly diffusing anti- 
septic. It appears to preserve stumps of pulps with which it is placed 
in contact. This oil has wide application in the treatment of septic pulp- 
canals and their chronic sequelae. 

Oxygen. 

Oxygen in gaseous form is combined with nitrous oxid (method of 
Hewitt) to reduce or prevent the occurrence of the lividity due to a de- 
privation of oxygen, when nitrous oxid is administered alone. Nascent 
oxygen is disengaged from compounds in which it is loosely combined, 
as the dioxids of hydrogen and sodium (see Hydrogen Dioxid), to act 
as a germicide, disinfectant, and bleaching-agent. Liberated from these 
compounds in contact with decomposing organic matter, the nascent 
oxygen seizes upon the hydrogen of such substances, effecting their 
decomposition. Nascent oxygen quickly destroys the vitality of bac- 



566 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



teria. Uniting with the hydrogen of staining substances, it effects a 
bleaching by their decomposition. 

Paraffin. 

Specimens of hard paraffin, those having high melting-points, are 
used either alone or combined with other substances, as iodoform or 
aristol, as canal-fillings. 

Phenacetin, C 10 H 13 NO 2 or C 6 H 4 (C 2 H 5 0)NH,C 2 H 3 0. 

Acetphenetidin or phenylacetin is a tasteless coal-tar derivative having 
greater antipyretic and analgesic powers than acetanilid. Dose, iij-x 
grains. 

Plumbum, Lead. 

The acetate, in the form of liq. plumbi subacetatis, is the basis of 
lead-water. It is an astringent antiphlogistic, producing contraction 
of bloodvessels of parts to which it is applied. It is a useful sedative 
antiphlogistic in cases where the inflammation from alveolar abscess 
has invaded the tissues of the cheek. It is applied externally. Inter- 
nally this solution is actively poisonous. 

The following is the well-known lead-water and laudanum mixture : 

Ify. Liq. plumbi subacet., Biv ; 

Tr. opii, 3j ; 

Aquse, Oj. — M. 

Sig. Applied on compresses to the inflamed parts. 

Potassium. 

Several potassium salts, and also the metal itself, are employed in 
dental therapy. The metal is used in alloy with metallic sodium to 
effect the quick decomposition of the products of putrefaction in pulp- 
canals. It seizes upon the hydroxyl elements of these substances, 
forming potassium and sodium hydroxids, which in their turn act upon 
the canal-contents, converting them into innocuous and soluble sub- 
stances. Applications of potassium sodium (kalium-natrium) should 
precede all attempts at tooth -bleaching, as the bulk of the offending 
material is thus removed, permitting the passage of nascent oxygen or 
chlorin to the deeper parts of the discolored dentin. 1 

Potassium bromid in doses of three grains is a useful remedy to 
lessen the reflex cerebro-spinal irritation of children due to teething. 
In cases of convulsion it is administered by the rectum in combination 
with chloral hydrate, suspended in starch mixture. A full dose, grs. 

1 Kirk. 



PYROZONE-SA CCHARIN. 567 

xx-xxx, will in many cases relieve the wakefulness accompanying pain- 
ful dental affections. 

Potassium carbonate in saturated solution in glycerin is a powerful 
obtundent of hypersensitive dentin. It is also antiseptic, destroying 
the putrid contents of pulp-chambers. 

Potassium chlorate in strong solutions is an effective agent in all 
forms of stomatitis. It is particularly valuable in mercurial stomatitis. 

Potassium hydrate, as a germicide and disinfectant, has been de- 
scribed above. 

A mixture of potassium hydrate and carbolic acid equal parts, lique- 
fied with alcohol, is a powerful obtundent of hypersensitive dentin. It 
is an irritant caustic (Robinson's Remedy). 

Potassium iodid in ointment is a useful application to indurations 
about the jaws, left as the result of chronic inflammations. 

1^. Potassii iodid., gr. xx ; 

Cerat. simp., 3j. — M. et ft. unguent. 

Potassium iodid is administered internally in cases of mercurial 
stomatitis, pericementitis, and periostitis, as an elimi native agent. 

Potassium permanganate is an effective oxidizing deodorant and 
antiseptic ; its germicidal power is very doubtful. In contact with 
organic matter it gives up its oxygen and is reduced to manganese oxid. 
It is a chemical antidote of morphin, and of snake- venom. 1 It is used 
in claret-colored solutions to deodorize an offensive mouth. 

Pyrozone. (See Hydrogen Dioxid.) 

QUERCUS. 

A tincture of quercus alba, or white-oak bark, diluted, is used as an 
astringent to reduce the tumidity of the gums. 

Quillaia, Soap-bark, 
is used powdered, as a substitute for powdered Castile soap in dentifrices. 

Resorcin, C 6 H 4 (HO) 2 . 

A close analogue of carbolic acid, C 6 H.HO. Is more poisonous than 
carbolic acid, and does not act so promptly. 2 Its uses are similar to 
those of carbolic acid. It is more soluble in water than the latter. 

Saccharin, C 6 H 4 (CO)(SO^NH, Benzoyl-sulphonic Imide. 
A coal-tar derivative more than two hundred times sweeter than 
1 S. Weir Mitchell. 2 Brunton. 



568 DENTAL PHARMACOLOGY AND MATERIA MEDICA. 

sugar ; it is antiseptic, checking fermentations. For this reason a 
minute portion is used as the sweetening agent in mouth-washes, instead 
of sugar. The solution must be made with alcohol. 

Salol, Phenyl Salicylate, C 6 H 4 (OH)(CO.OC 6 H 5 ). 

A white crystalline powder insoluble in water, melting at about 
105° F. ; it remains fluid for some time after reduction to a tempera- 
ture below that of the body. It is decomposed by alkalies into carbolic 
and salicylic acids. It has been used in its melted state as a root-canal 
filling. Administered internally in 5 gr. doses to relieve rheumatic 
pains about the jaws. 

Silver. 

Silver nitrate (argenti nitras) is employed in all strengths from a 1 
per cent, solution to the fused nitrate — the solid stick or lunar caustic. 
Nitrate of silver exposed to sunlight undergoes decomposition and is 
reduced to the oxid. Brought in contact with albuminous substances, 
silver nitrate combines with them, forming the albuminate of silver. It 
has been held by Avriters upon pharmacology that the action of silver 
nitrate applied to a surface was very superficial ; that a film of silver 
albuminate formed and the chemical reaction ceased. Experiments by 
Truman 1 have shown that its penetrative power is very great as com- 
pared with other coagulants. Placed at one end of a capillary tube 
containing a solution of albumin, silver nitrate quickly brings about 
coagulation to the extremity of the tube. 

It has long been used as an empirical remedy for traumatic erysip- 
elas, for which it has been held to be a specific. To act as a germicide in 
such cases its action must be penetrating, as the streptococci of erysipelas 
are deeply situated. 

Nitrate of silver, in saturated solution, is used to arrest caries in 
deciduous teeth (see Chapter XXVII.) and also to destroy hyper- 
sensitivity of dentin ; its deeply penetrative action suggests caution in 
this direction. It is never used except in posterior teeth because of its 
staining, owing to the reduction of the silver albuminate to silver oxid. 

In 5-10 per cent, solution it is used as a wash for pyorrhoea pockets 
in which pus-formation and congestion are persistent. 

Other salts of silver, notably the citrate and lactate, have been 
shown to be prompt and effective germicides. The silver citrate is 
soluble in the proportion of about 1 : 3800 in water, in which strength 
it is sufficiently active to sterilize the cavities of abscesses and as a wash 
in inflammatory and suppurative affections about the jaws. The stains 
upon the enamel are easily removable by means of common abrasives. 

1 Proc. Academy of Stomatology, 1895. 



SODIUM. 569 

The powdered silver citrate should make a valuable addition to the 
melted paraffin for use as a canal-filling in posterior teeth. 

The lactate of silver, soluble 1 : 15 in water, is slightly irritating. 

Sodium. 

The sodium salts are usually regarded as having therapeutic proper- 
ties similar to those of the potassium salts. Bartholow l maintains strongly 
that they differ in essential properties ; the sodium salts are more dif- 
fusible, are less irritating to mucous membranes, and are less toxic to the 
tissues, including the cerebral and circulatory centres. Potassium salts 
are more active in promoting destructive metamorphosis, and in removing 
inflammatory growths and promoting excretion. What has been said 
of the dental uses of potassium bromid, carbonate, and hydrate, and 
metallic potassium, applies, however, to the corresponding salts of 
sodium. 

Sodium biborate, borax, Na 2 B 4 7 + 10H 2 O, is used in solution with 
glycerin in the treatment of catarrhal and ulcerative stomatitis of 
children. 

Sodium bicarbonate, NaHC0 3 , is used in carious cavities to lessen 
dentinal hypersensitivity by neutralizing the acids to which the condition 
is probably due. 2 

Sodium phenate, phenol sodique, C 6 H 5 NaO, is used as an antiseptic 
and styptic. It is a local anaesthetic ; its common uses are those of 
carbolic acid, but it is without the cauterant action of the latter. 

Sodium peroxid, Na 2 2 , in contact with organic matter sets free 
nascent oxygen ; the sodium oxid left is quickly converted into sodium 
hydrate, having the properties of that substance. Solutions must be 
made gradually and in ice-cold distilled water, as the heat of combina- 
tion raises the temperature of the water, and oxygen escapes. A 
saturated solution is first made, which is afterward diluted with dis- 
tilled water. Powdered sodium dioxid is hygroscopic and is rapidly 
decomposed upon exposure to the air. In saturated solution (applied by 
means of aluminum, gold, or platinum points) it is used in the treat- 
ment of putrescent pulps, and as a bleaching agent for discolored den- 
tin. It possesses the properties of sodium hydroxid and nascent 
oxygen. 

Sodium sulfite, Na 2 S0 3 -f- 7H 2 0. A mixture of sodium sulfite, 
10 parts, and boric acid, 7 parts, made dry, is inserted into the cavity of 
a tooth in which the dentin is to be bleached ; when water is applied 
a reaction occurs, sulfurous acid being liberated : 

2H 3 B0 3 + 3Na. 2 S0 3 = 2Na 3 B0 3 + 3H 2 + 3S0 2 . 3 

1 International Clinics, 1898, vol. iv., 7th series. - Truman, 

3 Kirk, American Text-book of Operative Dentistry. 



570 DENTAL PHARMACOLOGY AND MATERIA MEDICA. 

Unlike sodium dioxid and chlorin, this substance S0 2 , bleaches by 
reduction, abstracting the oxygen from the pigment-molecule. 

Sodium silico-fluorid (salufer), Na 2 SiF 6 . Sodium silicate, liquid 
silex, Na 2 Si0 8 . The latter substance has antiseptic properties. In 
the former the antiseptic and deodorant properties are marked. Sodium 
silico-fluorid is soluble in about the proportion of 1 per cent, in water. 
In this strength it has been used in the treatment of putrescent pulps. 

Sozoiodol, C 6 H 2 (HS0 3 )I 2 OH, 

is a compound of iodin with paraphenol sulphonic acid. It is used as 
an antiseptic in pyorrhoea pockets. Miller's experiments 1 show that 
sozoiodol salts are but weak dental antiseptics. 

Thymol, 

a stearoptene derived from the volatile oil of thyme, is methy-prOpyl- 
phenol, C 6 H 3 (CH3)(C 3 H 7 )HO. It is soluble in alcohol and ether. It 
possesses the properties of a methyl phenyl — i. e., is markedly antiseptic 
and analgesic. It is extensively used as an analgesic and antiseptic in 
the treatment of diseases of the pulp. 

Trichlorphenol, C 6 H 2 C1 3 H0, 

is a powerful and penetrating antiseptic, stronger than carbolic acid. 
" It possesses the power of penetrating pulp-tissue rapidly, thoroughly 
hardening it and imparting to it a pink to red color. Its pulp-preserv- 
ing power is very high." 2 It is applied to pulps which have been but 
partially devitalized by arsenic, to sterilize them and complete their 
devitalization. 

Dental Varnishes. 

1^. Gum sandarac, gij ; 

Alcohol, Oj. 

Mix, and aid solution with heat. Filter solution through cotton- 
wool. 

This is used in the dental laboratory as a separating medium and to 
varnish casts. 

Pellets of cotton-wool dipped in the sandarac solution are used to 
cover medicinal applications in teeth and to prevent the ingress of 
foreign materials. Being in no degree antiseptic, and becoming foul 
after twenty-four hours or longer, soft gutta-percha preparations 
(temporary stopping) have largely superseded cotton and sandarac. 

1 Denial Cosmos, 1890. 2 Miller, Dental Cosmos, 1895. 



DENTAL VARNISHES. 571 

Renewed every day, cotton and sandarac dressings are useful to press 
away the gum overhanging the margins of cavities, to check alveolar 
hemorrhage, and to temporarily close the crowns of teeth under treat- 
ment. It is also used to varnish the walls of prepared cavities prior to 
inserting plastic fillings, to prevent the irritation incident to the applica- 
tion of zinc oxychlorid cement, and to prevent the irritation of zinc phos- 
phate in a soft state, due to its acid reaction in this condition ; and also 
to prevent the action of the acid upon dentinal walls. It is also used 
to prevent the action of acid substances which may be present as 
impurities in zinc-cement fluids, notably, the acid sodium phosphate, 
dihydrogen sodium phosphate (H 2 NaP0 4 ). 

SHELLAC VARNISH. 

The coloring, separating medium of the dental laboratory. 

]^. Gum shellac, ,§ij ; 

Alcohol, Oj.— M. 

Aid solution by heat. 

♦ 

In its unmodified form it has but little use aside from that of the 
first or coloring varnish applied to plaster impressions. It is used to 
apply to enamel-surfaces which have been cleansed with chloroform, to 
secure greater adhesion between orthodontic rings and the teeth. The 
tooth to which a " regulating ring" is to be applied is washed with 
chloroform, dried, and a coating of shellac varnish given to the part 
to be covered by the ring. The latter is painted with zinc-phosphate 
cement, which is also applied over the shellac coating, and the ring 
pressed into place ; the parts should be kept dry until the cement is 
hard. Combined with appropriate antiseptics shellac varnish makes 
an admirable protective covering to abraded surfaces of the mouth 
which might invite infection. 

The following formula (steresol) has been given by M. Berlioz, 1 of Gren- 
oble, France, for an adhesive, anaesthetic, antiseptic, impermeable coating 
to be applied over abrasions, wounds, etc., of the tissues of the mouth. 



It. 


Purified gum lac, 


270 gms., 


about 


5 ix; 




Purified gum benzoin, 


10 " 


a 


03 , 




Balsam of tolu, 


10 " 


u 


-1 . 
&3 > 




Oil of cinnamon (Chinese), 


6 " 


u 


05 » 




Acid, carbolic, 


100 " 


u 


#y ; 




Saccharin, 


6 " 


u 


3-5 > 




Alcohol, q. s. 


ft. one liter, 


u 


Oij. 



1 Dental Cosmos, 1895. 



572 



DENTAL PHARMACOLOGY AND MATERIA MEDICA. 



Veratrum Viride. 

Its tincture, in from 2 to 4 drop doses, is used to reduce the force 
of the circulation in the early stages of sthenic inflammations ; it is to 
be preferred to aconite in this connection, because it causes vomiting 
before a lethal dose has accumulated in the system. 1 



Veratrina. 

The paralyzant alkaloids of veratrina sabadilla, not of veratrum 
viride. There are at least three alkaloids entering into the compo- 
sition of commercial veratrina (U. S. Dispensatory). The U. S. P. 
(p. 204) ointment is used to rub over the temporo-maxillary articula- 
tion and over the masseter muscle to relieve spasm due to difficult 
eruption of the lower third molar. It should be used in small amount 
and be kept away from the mouth and eyes, as it is actively poisonous. 

Zinc. 

Zinc derivatives are among the most important therapeutic agents 
of dentistry. 

Zinc chlorid, ZnCl 2 , is very deliquescent ; it abstracts moisture 
from the atmosphere and becomes fluid soon after exposure. It com- 
bines readily and actively with albuminous substances, forming zinc 
albuminate. Applied to living tissues, the combination occurs promptly 
and is attended with much pain. 

Truman found 2 that its penetrative power in saturated solution was 
greater than that of any other coagulant. In from 10 to 20 per cent, 
solution it is a powerful astringent. The degree of astringency may be 
graded by varying the percentage- strength of the solution. In 1 to 5 
per cent, solution this substance is a stimulant, astringent, and germi- 
cide. It is used in full strength to obtund the hypersensitivity of 
peripheral dentin. In saturated solution it is the fluid of zinc-oxy- 
chlorid cement: 

ZnO + ZnCl 2 +H 2 = 2ZnClHO. 

A paste which hardens and maintains an antiseptic action for some 
time after hardening. Zinc chlorid, in 50 per cent, solution, or stronger, 
is used to coagulate the contents of the dentinal tubuli after devitaliza- 
tion and removal of the dental pulp. As a germicide, astringent, and 
stimulant, it is a useful agent in the treatment of pyorrhoea alveolaris ; 
also in cases of chronic abscess with serous exudations. 

Zinc iodid, in 20 per cent, solution, is an excellent application to 
pyorrhoea pockets in cases of phagedenic pericementitis, after the 
1 Hare. 2 Proc. Academy of Stomatology, 1895. 



ZINC. 573 

removal of calculi and the washing of the pockets (Harlan). It is an 
excellent stimulant wash for the same, in 2 per cent, solution for subse- 
quent applications. 

Zinc oxid is the basal powder of the zinc cements, the oxychlorid, 
the phosphate, and zinc oxysulfate. It may contain arsenic trioxid as 
an impurity, in which event cements made of it may kill the dental 
pulp. An ointment of zinc oxid is used upon abrasions about the lips. 

The orthophosphate of zinc, a combination of orthophosphoric acid 
with zinc oxid, is the most important of dental cements : 

3ZnO + 2H 3 P0 4 = Zn 3 (P0 4 ) 2 -f 3H 2 0. 

Zinc sulfate in saturated solution, if combined with a powder of zinc 
oxid, forms an oxysulfate of zinc, a body having about the hardness and 
porosity of plaster of Paris ; this compound is used to protect fully or 
partially exposed pulps. Zinc sulfate in 10 per cent, solution is a useful 
astringent wash in stomatitis. 

Black's 1-2-3 Mixture. 

Oil of cinnamon, 1 part ; 

Carbolic acid, 2 parts ; 

Oil of gaultheria, 3 parts. 



INDEX. 



ABNOEMAL food-supply as a disease- 
cause, 33 
Abnormalities of teeth, 206 
Abrasion of dentin, 261 

of teeth, 245 
Abscess, acute alveolo-dental, 394 
causes of, 394 
clinical history of, 398 
diagnosis of, 401 
discharge of, 395 
extension of, 398 
pathology of, 395 
pneumococcus in, 395 
prognosis of, 401 
pyaemia in, 402 
septicaemia in, 402 
stages of, 398 
sterilization in, 402 
symptoms of, 397 
tissue-destruction in, 395 
treatment of, 402 
chronic alveolo-dental, 407 
anatomy of, 411 
diagnosis of, 413 
pathology of, 407 
symptoms of, 413 
treatment of, 415 
chronic alveolar, aspiration of, 411 

without fistula, treatment of, 409 
upon deciduous teeth, treatment of, 498 
dental, amputation of root-apex, 416 
in cachectic persons, 401 
chronic, burrowing of pus in, 408 
diagnosis of, 408 
with fistula, 411 
opening beneath chin, 412 
into dental canal, 413 
on face, 412 
into nose, 414 
prognosis of, 409 
symptoms of, 408 
treatment of, 409 
opening in antrum, 400 
externally, 405 
in neck, 405 
in nose, 399 
stripping of periosteum in, 399 
treatment of, by electrolysis, 415 
by poultices, 401 
in eruption of third molars, 203 
gouty, upon teeth, 485 
maxillary, due to caries, 414 
to necrosis, 414 
to tooth-root, 414 
mode of formation, 91 



Abscess, scars from treatment of, 419 

venting of, 93 
Acetanilid, composition of, 539 

uses of, 545 
Acid, acetic, 545 

arsenious, 546- 
antidote for, 546 
mode of action of, 546 

benzoic, 546 

boric, 546 

carbolic, 547 

chromic, 547 

gallic, 547 

hydrochloric, 547 

lactic, 547 

nitric, 548 

oxalic, 548 

phosphoric, 548 

salicylic, 548 

sodium phosphate in erosion, origin of, 251 

sulfuric, 548 
aromatic, 548 

sulfurous, 549 

tannic, 549 

trichloracetic, 545 
Acids, 545 

Aconite tincture, 549 
Aconitine, 550 

ointment of, 550 
Actinomycosis, 522 
Agenesia, 51 
Alcohol, ethyl, 550 

methyl, 550 

phenyl. (See Carbolic acid.) 
Alexins, 50 
Alpha^naphtol, 564 
Alum, potash, 550 

ammonia, 550 
Alveolar atrophy, 457, 458 

caused by salivary calculus, 453 

process, form of, 161 
growth of, 123 
Amalgam-fillings, poisoning by, 314 
Amalgams, properties of, 314 
Ameloblasts, contents of. 114 
Ammonium carbonate, 551 

hydrate, 551 

nitrate, 551 
Ammonol, 551 
Amoeba, functions of, 19-21 
Amyl nitrite, 551 
Anaemia, 69 

effects of, 34 
Anaesthetics, 537 

local, 539 

575 



576 



INDEX. 



Anaesthetics, local, composition of, 540 

mode of action of, 537 
Analgesics, 529 

definition of, 538 
Angina pectoris, nature of, 76 
Anodynes, action of, 537-539 
Antifebrin, 545 
Antipyrin, 551 
Antiseptic oils, 565 
Antiseptics, 529 

alcohols and derivatives as, 531 

caustic alkalies as, 531 

classification of, 530 

as dentifrices, 324 

essential oils as, 531 

halogens and their compounds as, 531 

heat as, 531 

mineral acids as, 531 

mode of action of, 530 

nascent oxygen as, 531 

organic acids as, 531 

salts of metals as, 530 

strength admissible in mouth-washes, 325 
Antrum, discharge of abscess into, 400-412 

empyema of, treatment of, 418, 419 
Aphthae, 516 
Aplasia, 51 
Aristol, 552 
Arsenic, absorption of, by pulp, 368 

accidents with, 377 
treatment of, 377 

antidotes for, 377 

effects of combinations, 371 
of combining coagulants, 371 
upon pulps, 368 
upon nerve-fibres, 368 
when nodules are present, 370 

form in which used, 371 

guarding gum-tissue from, 371 

idiosyncrasies as to action of, 371 

in immature teeth, 370 

to lessen pain of application of, 373 

mode of applying, 372 

rules for using, 371 

in temporary teeth, 370 

variations as to action of, 370 
Arsenical pastes, 367 
Arteries, calcification of, Q6 

nervous control of, 76 

terminal, occlusion of, 72 
Astringents, 540 

mode of action of, 541 
Atheroma, 66 
Atrophy, causes of, 61 

nature of, 61 

physiological, 61 
Atropia, chemical relations of, 540 

BACILLI, 39 
Bacillus tuberculosis, effects of, 64 
Bacteria, chissification of, 39 
conditions of life of, 39 
decompositions effected by, 43 
effects of, on tissues, 190 
infective, of mouth, 511 
ingestion of, by amoebae, 20 
mode of entrance to body, 90 



Bacilli of the mouth, 45-47 

pathogenic, 40 

physiology of, 38 

place of, in nature, 38 

pyogenic, 45 

saprophytic, 40 

waste-products of, 42, 43 

where found, 44, 45 
Bacteriology, history of, 37 
Bell on caries, 265 
Benzoyl as an analgesic nucleus, 540 
Beta-naphtol, 564 
Bicuspids, architecture of, 143 

impacted, 237 

imprisoned, 229 

mechanics of, 170 

surgical relations of, 160 
Black on structure of teeth, 279 
Black's 1-2-3 mixture, 573 
Blastomycetes, pathogenic, in mouth, 511 
Bleaching-powder (Kirk's), 549 
Blood, abnormal composition of, 69 

alterations in, 71 

coagulation of, 71, 72 

conditions of, 69 

effects of waste-products on, 69 

number of red corpuscles of, 70 

office of oxygen in, 69 
of red corpuscles of, 70 

phagocytes of, 73 

-supply, lessened, causes of, 74 

-vessels, degenerative changes in, 63 
Bodecker, theories of, 272 
Bone, first appearance of, in jaw, 108 

interstitial development of, 108 
Borax, 552 
Boroglycerin, 553 
Bridgmann on caries, 266 
Bromid of sodium, 553 

of potassium, 553 

iHAFFEIN, 553 

\J Calcareous degeneration, 65 

effects of, 330 
Calcification, tubular, causes of, 330 
Calcium carbonate, 553 
chlorid, 553 
hypochlorite, 553 
hypophosphites, 553 
oxid, 553 
Calco-globulin, 113 

deposits in pulp, 336 
Calco-spherites, 113 
Calculi, subgingival, 456 

as cause of pyorrhoea, 457 
composition of, 456, 457 
effects of, 457, 458 
occurrence of, 457 
Calculus, salivary, 447 
causes of, 448 
effects of, 452 
formation of, 449, 450 
upon incisors, origin of, 451, 452 
upon molars, origin of, 451 
occurrence of, 447 
prognosis of effects of, 454 
in scales beneath gum, 452 



INDEX. 



577 



Calculus, salivary, structure of, 452 
treatment of, 454 
use of acids to remove, 454 
varieties of, 447 
Camphor liniment, 554 

spirits of, 554 
Campho-phenique, 554 
Canal-filling, 376 
Canals, root-, lining of, with silver nitrate, 

390 
Cancer, 59 
Cancrum oris, 517 
Canker sore, 516 
Cantharides, 554 
Capsicum, 554 

and myrrh, 555 
Carcinomata, 59 

Caries, arrangement of teeth influencing, 
280 

Bell's theory of, 262 

Bridgmann's theory of, 266 

casts of tubules in, 301 

cavity preparation, 316 

of cementum, 302 

changes of saliva influencing, 280 

clinical history of, 281 

deep-seated, 317 

defects of teeth and, 218 

dental, 264 

acids in, 265, 266-272 

of dentin, 298 

destruction of dentin-matrix in, 300 

diagnosis of, 304 

dressing enamel-surfaces, 315 

effects of disease upon, 277 
upon pregnancy, 276 
of starches on, 274 
of sugars on, 274 

of enamel, 291 

endangered pulps in, 318 

exciting causes of, 273 

extensive, with small orifices, 315 

fermentation and, 265 

formation of cavities, 305 

forms of teeth influencing, 279 

fourth stage of, treatment of, 319 

Fox's theory of, 265 

general predisposing causes of, 276 

history of theories of, 264 

Hunter's theory of, 265 

inception of, 281 

inflammatory theory of, 265 

influence of heredity upon, 277 

invasion of tubules, 300 

lactic acid in, 270 

leaving softened dentin in, 318 

Leber and Rottenstein' s theory of, 268 

local predisposing causes of, 277 

Miller on compatibilitv theory of, 266 

Miller's theory of, 268* 

Milles and Underwood's theory of, 268 

at necks of teeth, 289 

Palmer's theory of, 266 

pathology of, 290 

pigmentation in, 302 

predisposing causes of, 275 

prognosis of^ 312 

37 



Caries, prophylaxis of, 322 

rapidity of its progress, 287 

Robertson's theory of, 265 

second stage of, treatment of, 317 

secondary dentin in, 333 

signs of, 304 

situations in which found, 282 

spontaneous arrest of, 288 

sterilization of dentin in, 318 

sugars as a cause of, 274 

superficial, treatment of, 315 

symptoms of, 305 

third stage of, treatment of, 318 

Tomes' theory of, 265 

transverse process of, 301 

treatment of, 313 

tubules of dentin in, 300 

usually absent in erosion, 289 

variations in progress of, 288 

Watt's theory of, 267 
Cartilage of Meckel, 104 
Caryophyllum, oil of, 565 
Caseation, 64 
Cassia, oil of, 565 
Casts of tubuli, 301 
Cataphoresis, 544 

in canal-treatment, 391 

cocain, 311 

in pulp-extirpation, 367 
Cavities, carious, preparation of, 316 

lining of, 318 
Cell-functions, special, 23 
Cements, acid reaction of, 318 
Cementoblasts, 118-139 
Cementoclasts, 139 
Cementum, abnormalities of, 214 

caries of, 302 

formation of, 117-135 

histology of, 135 

nourishment of, 158 
Chancre of mouth, 519 
Chemotaxis, negative, 49 

positive, 49 
Chemotaxtic properties of saliva, 49, 50 
Children, difficulties in operating upon, 
492 

management of, 492 
Chloral hydrate, 555 
Chloroform, 555 

dangers of, in dentistry, 538 
Chlorophyll, properties of, 38 
Cinnamon, oil of, 565 
Circulation in disease, 34 
Clasps, effects of wearing, 245 
Cleft palate, 104 
Cloudy swelling, 62 
Cloves, oil of, 565 
Coagulation limiting diffusion, 535 

-necrosis, 68 
Cobalt, 555 
Cocain, 555 

chemical relations of, 540 
injection of, formula for, 556 
into pulp, 367 
Cold, effects of, on vitality, 21 
Colic in teething, 191 
Collodion, 556 



578 



INDEX. 



Colloid degeneration, 65 
Concrescence of teeth, 217 
Convulsions, teething-, 188 
Copper oxid, 556 

sulfate, 557 

tooth-staining by, 256 
Coronoid process, growth of, 121 
Corrosive sublimate, 562 
Cotton, absorbent, preparation of, 557 
Cough, teething-, 187 
Counter-irritants, use of, 79 
Creosote, 557 
Cresols, 557 
Cuspids, architecture of, 142 

impacted, 236 

mechanics of, 168 

upper, treatment of impacted, 241 
Cusps, supplemental, 217 

DEAFNESS caused by dental diseases, 507 
Degenerations, calcareous, 65 
causes of, 62 
colloid, 65 
fatty, 63 

causes of, 63 
granular, 62 
hyaline, 65 
inflammatory, 60 
mucoid, 65 
Dental band, 106 
caries, 264 
cords, 107 
groove, 106 
lamina, 107 
pain arising from other diseases, 509 

origin of, 502 
ridge, 106 
Dentifrices, 323 
tooth-pastes, 324 
tooth-soaps, 324 
use of antiseptics in, 324 
Dentin, abrasion of, 261 
absorption of, 263 
action of acids on, 127, 146 
basis of, 128 

calcium salts in, amount of, 145 
caries of, 298 
acid in, 298 

destruction of organic matrix, 300 
softening prior to infection, 298 
changes with age, 145 
chemical nature of, 146 
density of, 145 
diseases, classification of, 260 

constructive, 260 
erosion of, 261 

exposed, reflex pains from, 502 
fibrillae of, 147 
formation of, 116 
granular layer of, 129, 212 
hypersensitivity of, 305 
causes of, 306 
pathology of, 306 
symptoms of, 307 
treatment of, 308 
alkalies, 309 
analgesics, 310 



Dentin, hypersensitivity of, treatment of, 
anodynes, 308 
cataphoresis, 311 
caustics, 309 
cold, 309 
dryness, 309 
obtundents, 310 
interglobular spaces in, 129, 212 
mineral basis of, 146 
organic matter of, 145 
physical strength of, 145 
resorption of, 262 
recalcification of, in caries, 300 
retrogressive changes in, 146 
secondary, 261, 33i 
in abrasion, 333 
in caries, 333 
causes of, 332 
pathologv of, 332 
Tomes' fibres, 129-133 
transitional, 134 
translucent, 261 
tubular calcification of, 330 
Dentinal tubuli, 126 
Dentition, hygiene of, 185 

intestinal disturbances in, 186, 187 
multiple, 225 

nervous disorders during, 187, 188 
pathological, 185 
symptoms of, 185-188 
treatment of, 188-194 
process of, 181 

pulmonary symptoms in, 187 
second, 195 

disorders of, 199 
skin-disorders in, 187 
third, 225 
Deodorants, action of, 530 
Devitalizing fibre, 374 
Devitalization of pulp, 367 
Diabetes, influence of, upon caries, 277 
Diarrhoea of teething, 190 
Diet of gouty patients, 489 
Disease-causes, abnormal food-supply, 33 
abnormal physical conditions, 35 
nature of exciting, 32 
poisons as, 34 
Diseases, causes of, 35 
classification of, 24 
functional, 23, 24 
general, and dental caries, 277 

definition of, 36 
immunity from, 31, 32 
local, definition of, 36 
objective evidences of, 24 
pathology of, 24 
predisposing causes of, 29, 32 
age, 30 

existing disease, 30 
heredity, 30 
previous disease, 31 
sex, 30 

temperament, 30 
prophylaxis of, 27 
structural, 24 
subjective evidences of, 24 
Disinfectants, definition of, 530 



INDEX. 



579 



Dobell's solution, 552 
Dwarf teeth, 215 

EDENTULOUS persons, 224 
Electricity, chemical effects of, 543 
in dental therapeutics, 542 
physiological effects of, 542 
Electrolysis in dental therapeutics, 543 

in treatment of abscesses, 415 
Emboli, infective, 99 
Embolus, 72 
Enamel, abrasion of, 245 
arrangement of, 142-144 
caries of, 291 

organisms of, 292-298 
relations of bacteria to, 297 
second stage of, 295 
situation of acids, 292 
cement-substance of, 115 

solubility of, 125 
changes in, after eruption, 115 
-cracks, 242 

decalcification of, without cavities, 294 
dentinal process in, 209 
-deposition, 116 
development of, 109 
diseases of, 242 
faulty, about sulci, 209 
fracture of, 242 
-globules, 115 
histology of, 123 
injury of, 243 
lines of cleavage of, 244 
malformations of, 206 
-organ, evolution of, 111 
formation of, 108 
stellate reticulum of, 112 
stratum intermedium of, 113 
structure of, 111 
perfect, 206 

pigmented lines in, 210 
-prisms, 123 

of pulpless teeth, strength of, 244 
resistance of, chemical, 144 

physical, 144 
-rods, 123 

action of acids on, 124 
arrangement of, 125 
solution of, 259 
stains of, 255 

treatment of, 258 
stratification of, 210 
strength of, 142 
stripe of Retzius, 125 
striation of, 125-210 
a non-vital tissue, 141 
syphilitic, 210, 211 
white spots in, 207 
Encapsulation of foreign bodies, 54 
Encysted teeth, 231 
Epithelioma, 59 
Ergot, 558 
Erigeron, 558 
Erosion, 247 

appearances of, 253 
causes of, 248-251 
causes of appearance, 252 



Erosion of dentin, 261 

diagnosis of, 254 

morbid anatomy of, 252 

symptoms of, 254 

treatment of, 254 
Eruption, periods of, 182 
Eruptive fevers, teeth of, 211 
Ether, ethylic, 558 
Ethyl chlorid, 558 
Eucain, 558 

chemical relations of, 540 
Eucalyptus, oil of, 565 
Eugenol, 565 

Evolution, higher, of cell-properties, 22 
Exostosis of tooth-roots (hypercementosis), 

428 
Exudations, inflammatory, 178 
Eye, diseases of, caused by dental diseases, 
508 

FATTY degeneration, 63 
in inflammation, 64 
in tumors, 64 
of vessels, 64 
Fermentation, conditions of, 42 

nature of, 41 
Ferments, organized, 44 

unorganized, 44 
Fever, 95 
causes of, 95 
classes of, 95 

pathology and morbid anatomy of, 95 
prognosis of, 95 
symptoms of, 95 
treatment of, 95 
Fibres, Sharpey's, in cementum, 136 
Fibrillar of dentin, 147 
Filling-materials, properties of, 313 
Fistula, artificial, establishing, 404 
Follicle, dental, 109 
Follicles, labial, 250 

formation of, 410 
Follicular wall, 111 
Foreign bodies, fate of, in tissues, 54 
Formalin, 559 
Fox on caries, 265 

Fungous pulp. (See Pulp, Hypertrophy of.) 
Fused teeth, 216 
pulps of, 217 

GANGRENE, dry, 68 
moist, 68 
of mouth, 517 
of pulp, 381 
Gaultheria, oil of, 565 
Geminous teeth, 217 
Germicides, mode of action of, 531 
Giantism of teeth, 214 
Gingival organ, 137 

Gingivitis, caused by foreign bodies, 445, 446 
local, causes of, 445 
marginal, 444 
causes of, 444 
and general diseases, 445 
prognosis of, 446 

relations with pericemental diseases, 446 
symptoms of, 446 



580 



INDEX. 



Gingivitis, treatment of, 446, 447 
Glycerin, 559 

Gold, advantages of, as a filling, 314 
Gout, causative of pericemental irritation, 

436 
points of attack of, 482 
-poison, mode of action, 480 

selective action of, 482 
treatment of, 487 
Gouty diathesis and erosion, 249 

pericementitis, 477 
Granulation-tissue, 87 
Green stain, 257 

causes of, 257 

coloring-matter of, 258 

decalcification under, 257 
Grooved teeth, 215 
Guaiacol, 559 
Guaia-cocain, 559 

Gum, inflammation of, in dentition, 202 
-lancing, 192, 193 

hemorrhage after, 194 
Gumma in mouth, 521 
Gums, structure of, 137 
Gutta-percha, properties of, 315 

HAEMOGLOBIN, deficiency of, 70 
Hamamelis, 559 
Harelip, cause of, 103 
Harting on calco-globulin, 113 
Hemorrhagic infarct, 72, 73 
Herbst method of treating pulps, 372 
Hernia of pulp, 223 
Hertwig, O., on protoplasm, 18, 19 

root-sheath of, 118-136 
Homatropin, its chemical relations, 540 
Honeycombed teeth, 212 
Hunter on caries, 265 
Hutchinson teeth, 218 
Hyaline degeneration, 65 
Hydrogen dioxid, 560 
Hydronaphtol, 564 
Hyperemia, 69-75 
arterial, 77 
causes of, 77 
exudations in, 78 
pathology of, 78 
results of, 78 
symptoms of, 78 
treatment of, 78, 79 
a predisposition to infection, 91 
of pulp, active, 341 
venous, 79 
causes of, 79 
morbid anatomy of, 79 
pathology of, 79 
symptoms of, 79 
treatment of, 80 
Hypercementosis, 428 
causes of, 428 

causing reflex neuralgia, 505 
diagnosis of, 431 
histology of, 431 
morbid anatomy of, 429 
pathology of, 429 
symptoms of, 431 
treatment of, 432, 433 



Hypernutrition, effects of, 52 
Hyperplasia, 52 

causes of, 52, 53 

from disuse, 53 

from overwork, 53 
Hyperpyrexia, 95 
Hypersensitivity of dentin, 305 
Hypertrophy, 52 
Hypodermatic medication, 544 
Hyponutrition, effects of, 61 

IMPACTED cuspids, 236 
J_ bicuspids, 237 

incisors, 237 

teeth, 231 

causing neuralgia, 507 

third molars, lower, 231 
upper, 235 
Imprisoned bicuspids, 229 
Incisors, architecture of, 142 

impacted, 237 

mechanics of, 168 

surgical relations of, 159 
Incompatibles in prescriptions, 541 
Infarct, hemorrhagic, 72, 73 
Infarction of pulp, 347 
Inflammation, catarrhal, 84 

causes of, 80, 83 

changes in, 81 

definition of, 80, 83 

diapedesis in, 82 

exudations of, 81 

fatty degeneration in, 64 

induced by streptococci, 92 

infective, 89 

interstitial, 84 

Metchnikoff's theory of, 82-89 

parenchymatous, 84 

pathology of, 81 

phagocytosis in, 82 

regeneration after, 85 

serous, 84 

symptoms of, 83 

terminations of, 82 

treatment of, 84 
bloodletting in, 85 
cold in, 

varieties of, 83, 84 
Inflammatory degeneration, 60 

origin of cells, 82 
Inoculation, history of, 32 
Insanity due to dental diseases, 509 
Interglobular spaces, 129, 147, 212 
Interstitial inflammation, 83 
Intestinal poisons, effects of, 71 
Intoxication, septic, 95 
Iodids, 560 
Iodin, 560 

compounds, action of, as antiseptics, 535 
Iodoform, 560 
Iodol, 561 
Iron salts, 561 

tooth-staining by, 256 
Ischsemia, 69 

JAWS, architecture of, 173 
development of, 101 



INDEX. 



581 



Jaws, earliest appearance of, 102 
mode of growth of, 102 

KARYOKINESIS, 21 
Kino, tincture of, 561 
Kirk on origin of acid in erosion, 
Krameria, tincture of, 561 



251 



LABIAL follicles, 250 
glands, 250 
secretion of, 250 
Lateral incisors, upper, non-development of, 

165 
Lead, 

acetate as an astringent, 541 
tooth-staining by, 256 
-water and laudanum, 
Leeuwenhoek on bacteria, 47 
Leucocytes, varieties of, 73 
Leucocytosis in suppuration, 74 
Liquefaction-necrosis, 68 
Listerism, 37 

Lithium bitartrate in gout, 488 
Lymphadenitis following dental abscess, 401 
Lymphatic infection, 98 
Lysol, 561 

MAGNESIUM, 562 
hydrate, 562 
hydrate in erosion, 255 
sulfate, 562 
Malformations of teeth, 206 
Malpositions of teeth, 227 

causes of, 228 
Manganese, tooth-staining by, 256 
Mastication, mechanism of, 176 
Materia medica of dentistry, classification 

of, 529 
Maxilla, inferior, architecture of, 173 
blood-supply of, 163 
mechanics of, 175 
size of, at different ages, 120 
Maxilla?, later development of, 119 
superior, architecture of, 173 
blood-supply of, 164 
growth of, 121 
Meckel's cartilage, 104 

atrophy of, 104-119 
Membrane, Nasmyth's, 141 
Menthol, 562 

Mercurial pericementitis, 436 
Mercnrialism from amalgam, 314 
Mercuric chlorid in putrefaction, 532 
Mercury bichlorid, 562 
oxid, ointment of, 563 
sulfid, 563 

tooth-staining by, 256 
Metallic salts, germicidal action of, 534 
Metastasis of tumors, 60 
Metchnikoff on phagocytosis, 48, 49 
Metchnikoff's theory of inflammation, 82-89 
Methyl chlorid, 563 
Micrococci, classes of, 39 
Miller on caries, 268 

experiments of, in fermentation, 269 
Milles and Underwood on caries, 268 
Molars, first, eruption of, 197 



Molars, fourth, 225 

first, premature loss of, effects of, 230 

care of, 231 
mechanics of, 170 
pathological eruption of, 201 
causes of, 201 
treatment of, 201 
permanent, eruption of, 201 
roots, anatomical relations of, 161 
second, eruption of, 199 
surgical relations of, 160 
third, architecture of, 143 
late eruption of, 224 
lower, extraction of, 204 
impaction of, 231 
Morphia, 563 

Motor disturbances of dental origin, 508 
Mouth, bacteria of, pathogenic, 48 
ferments of, 275 
infection from, 99 
infections of and from, 511 
phagocytosis in, 99 
Mucin, coagulation of, by lactic acid, 281, 448 
Mucoid degeneration, 65 
Mucous patches, 520 
Mummification of pulp, 378 
Muscles, stiffness of, in dentition, 202 
Myrtol, 565 

NAPHTHA LIN, 564 
Naphtol, 564 
Nasmyth's membrane, 116-141 

and caries, 278 
Necrobiosis, 68 
Necrosis, 66 

causes of, 66 

coagulation-, 68 

in eruptive fevers, 199 

of inferior maxilla, 66 

liquefaction-, 68 

of lower jaw, 66 

nature of, 67 

predisposing factors in, 67 
Nerve, fifth cranial, plan of, 501 

-terminals in pulp, 135, 148 
Nerves, trophic, 35 

vasomotor, 35 
Nervous disorders of teething, treatment of, 

191, 192 
Neumann, sheaths of, 127 
Neumann's sheaths, solubility of, 260 
Neuralgia caused by impacted teeth, 507 

of dental origin, 500 

from dental sources, mechanism of, 505 

from hypercementosis, 432 

from pulp diseases, location of pain, 504 
Neuralgias, reflex, from pulp diseases, 503 
Nickel, tooth-staining by, 256 
Nitrous oxid, 565 
Nodules, pulp-, 334 

effects of arsenic in cases of, 370 
Noma, 517 

pathology of, 517 
Nucleus, division of, 21 

OBTUNDENTS, definition of, 538 
of dentin, 310 



582 



INDEX. 



Occlusion, laws of, 176 

plane of, 177 
Odontitis infantum, 186 
Odontoblasts, 131-133 

arrangement of, 132, 133 

atrophy of, 156 

effects of stimulation on, 155 

function of, 117 

penetrating enamel, 117 

relations of, with nerve-terminals, 148 
Odontoclasts, 139 

office of, 198 
Odon tomes, 220 

classification of, 221 

origin of, 221 

treatment of, 223 
Oi'dium albicans, 511 
Oil of cassia, 565 

of cinnamon, 565 

of cloves, 565 

of eucalyptus, 565 

of gaultheria, 565 

of myrtle, 565 

of thyme, 565 
Oils, antiseptic, 565 

essential, action of, as obtundents, 540 
1-2-3 mixture (Black), 573 
Ord on calco-globulin, 113 
Organs, nature of, 23 
Osteoclasts, 139 
Osteodentin in pulp, 339 
Osteomyelitis, 91 

causes of, 91 

morbid anatomy of, 94 

pathology of, 94 

symptoms of, 94 [ 

treatment of, 95 
Oxidation in cells, 23 
Oxygen, nascent, 565 

PAIN, dental, referred to distant nerves, 
507 
reflex, nature of, 500 
Palate, cleft, 104 

development of, 103 
Palmer on caries, 266 
Paraffin, 566 

as a canal-filling, 376 
Parasitic bacteria, 40 
Parenchymatous inflammation, 83 
Pastes, mummifying, 380 
Pasteur on bacteria, 37 
Pericementitis, acute, bloodletting in, 404 
septic apical, 394 
treatment of, 402 
apical, chronic, non-septic, 427 
causes of, 427 
diagnosis of, 428 
effects of, 428 
prognosis of, 428 
symptoms of, 427, 428 
treatment .of, 428 
beginning at apex, 394 
upon deciduous teeth, 498 
general aseptic, 435 
acute, 435 
causes of, 435 



Pericementitis, general aseptic, acute, clin- 
ical history of, 435 
diagnosis of, 436 
prognosis of, 436 
symptoms of, 435 
treatment of, 436 
chronic, 437 
causes of, 437 
gouty, 477 

clinical history of, 477 
concretions of, 485 
definition of condition, 477 
diagnosis of, 480 
earliest evidences of, 478 
features of, 479 
history of theory, 477 
pathology of, 483 
points of attack, 485 
prognosis of, 486 
symptoms of, 477 
mercurial, 436 

non-septic, classification of, 423 
septic apical, chronic, 407 
diagnosis of, 412 
non-purulent, 420 
symptoms of, 421 
treatment of, 421 
causing reflex pains, 506 
sedatives in, 404 
traumatic, acute, 423-427 
causes of, 423, 424 
clinical history of, 425 
diagnosis of, 425 

pathology and anatomy of, 425, 426 
prevention of, 424 
symptoms of, 425 
treatment of, 426, 427 
due to root-perforation, 427 
Pericementum, apical, 139 
arrangement of fibres of, 137 
cells of, 139 

classification of diseases of, 393 
diseases of, diagnosis of, 394 

evidences of, 393 
epithelium in, 139 
functions of, 136-140 
histology of, 136-140 
as a ligament, 138 
nerves of, 140-158 
nerve-terminations in, 140 
office of, 157 

Pacinian corpuscles in, 140 
the tactile organ of the teeth, 146 
vascular supply of, 157 
vessels of, 239 
Periosteum, first evidences of, 108 
Periostitis in dental abscess, 406 

infective, 95 
Peroxid of hydrogen, 560 
Phagedenic pericementitis, 460-468 
alveolar process in, 472 
causes of, 469 
definition of, 469 
diagnosis of, 473 
earliest evidences of, 469, 470 
gum-atrophy in, 473 
morbid anatomy of, 471 



INDEX. 



583 



Phagedenic pericementitis, pathology of, 471 
prognosis of, 474 
recession of gum-margin in, 470 
sponge-grafts in, 476 
symptoms of, 469, 470 
tooth-movement in, 469 
treatment of, 474 
Phagocytes, 73 
Phagocytosis, history of, 48 
in inflammation, 82-89 
Metchnikoff on, 48, 49 
in the mouth, 99 
Pharmacopoeia, dental, 545 
Phenacetin, 566 
Phenol sodique, 569 

Physical conditions, abnormal, as disease- 
causes, 35 
Pigmentation in caries, 302 
Piperazin in gout, 488 
Pitted teeth, 215 
Plants, classification of, 38 
Plenciz on bacteria, 37 
Plethora, asthenic, 75 

sthenic, 75 
Pneumococcus in alveolo-dental abscess, 395 
Potassium bromid, 553 
carbonate, 567 
chlorate, 567 
hydrate, 567 
iodid, ointment of, 567 
salts, action of, 566 
Pregnancy, effects of, upon teeth, 146 

upon caries, 276 
Pre-maxilla, origin of, 103 
Primitive teeth, 215 
Processes of Tomes, 147 
Prophylaxis of disease, 27 
Pseudopodia of amoebae, 19 

of leucocytes, 20 
Pulp, abscess of, 357 
arteries of, 135, 156 
calcareous degeneration of, 334 
calcific degeneration of, 338 
causes of, 338 
pathology of, 339 
-capping, 321 

materials used, 321 
results of, 322 
capillaries of, 156 
-chambers, 148 
forms of, 149, 150 
resorption of walls of, 365, 366 
changes in matrix of, 134 
chronic degenerations of, 362 
cocain injections into, 367 

-cataphoresis in, 367 
congestion of, 346 
degenerations of, chronic, symptoms of, 

366 
deposits of calco-globulin in, 336 
destruction of, by arsenic, 367 

by caustics, 367 
devitalization of, 367 
analgesics in, 374 
anodynes in, 374 
arsenic in, 367 
cobalt in, 372 



Pulp, devitalization of, removal after, 374 
diseases of, causing reflex neuralgias, 503 

classification of, 327 
distinction of deposits in, 339 
divisions of, 148 
effects of arsenic upon, 368-371 
exposure of, 320 
diagnosis of, 320 
prognosis of, 320 
treatment of, 321 
extirpation of, treatment of canals aftei\ 

376 
-fibres, nature of, 134 
fungous, 364 

polypus of, 364 
gangrene of, 381 
dry, 381 

causes of, 381 
pathology of, 381 
symptoms of, 382 
treatment of, 382 
moist, 383 
causes of, 383 
with open cavities, 384 
without caries, 386 
organisms in, 384 
partial, 387 

pericementitis following, 388 
in pyorrhoea, 386 
symptoms of, 386 
treatment of, 387 
under fillings, 385 
hemorrhagic infarction of, 347 
hernia of, 223 
histology of, 131-135 
hypersemia of, active, 341 
anatomy of, 342 
bloodvessels in, 342 
causes of, 341 
diagnosis of, 344 
idiopathic, 346 
pathology of, 342 
prognosis of, 344 
symptoms of, 341 
treatment of, 345 
passive, 346 

pathology of, 346 
prognosis of, 347 
symptoms of, 347 
treatment of, 347 
hypertrophy of, 364 
calcification of, 365 
diagnosis of, 366 
pathology of, 364, 365 
transplantation of epithelium in, 365 
treatment of, 366 
infarction of, 73 
inflammation of, 348 

chronic, 362 
malformations of, 213 
mummification of, 378 
nerves of, 132-135 
neural system of, 135 
-nodules, 334 

influence of, upon action of arsenic, 370 
occurrence of, 335 
pathology of, 335 



584 



INDEX. 



Pulp-nodules, structure of, 335 
symptoms of small, 337 

of large, 337 
treatment of, 339 
Pulp, no lymphatics in, 131 
osteodentin in, 339 
partial removal of, 378 

Herbst method, 372 
putrescence of. (See Moist gangrene.) 
reflection of sensations, 502 
reflex pains in, 157, 502 
refrigeration of, 367 
reticular atrophy of, 362, 363 
sclerosis of, 362 

treatment of, 363 
sensory function of, 156 
stroma of, 157 
structure of matrix, 134 
suppuration of, 354 
bacteria in, 354-357 
causes of, 354 
diagnosis of, 359 
evacuation of pus in, 361 
morbid anatomy of, 355 
prognosis of, 359 
symptoms of, 359 
treatment of, 360 
ulceration of, 356 
vascular system of, 134, 135 
veins of, 132, 134, 156 
-walls, resorption of, 263 
Pulpitis, acute, 348 
causes of, 349 
diagnosis of, 352 

pathology and morbid anatomy of, 350 
prognosis of, 353 
symptoms of, 352 
treatment of, 353 
chronic, 362 

hypertrophic, 364 
in deciduous teeth, 496 
Pulps, absence of response in, 330 
constructive diseases of, 330 
reasons for reflex pains in, 328 
shapes of, 151-155 
thermal test of, 328 
Pulse, 75 

variations of, 76, 77 
Pus, burrowing of, in alveolar abscess, 412 
Putrefaction of tissues, 68 
Pyaemia, 98 
causes of, 98 
in dental abscess, 402 
of dental origin, 523 
symptoms of, 99 
treatment of, 99 
Pyogenic bacteria, 45 
cocci, 90 

membrane in dental abscess, 407 
Pyorrhoea alveolaris. 459 
bacteria in, 459 
beginning at gum-margin, 460 
causes of, 460 
clinical history of, 460 
diagnosis of, 464 
morbid anatomy of, 462 
pathology of, 462 



Pyorrhoea alveolaris beginning at gum- 
margin, prognosis of, 465 
symptoms of, 460 
treatment of, 465-468 

classes of, 459, 460 

death of pulps in, 461 

differential diagnosis of, 464, 465 

distinctions of classes, 460 

meaning of, 459 

mode of scaling, 466 

nature of, 444 

splints for teeth in, 465, 466 

use of drugs in, 467, 468 

varieties of, 459 
Pyrozone. (See Hydrogen dioxid.) 

QUERCUS, 567 
Quillaia, 567 

RACHITIS, effects of, upon dentition, 194 
Radiograph of impacted teeth, 239 
Rainey on calco-globulin, 113 
Reflex pains, dental, 500 

from general diseases, 500 
diagnosis of, 506 
facial, origin of, 503 
from pericemental diseases, 503 
from pulp diseases, 503 
referred to teeth, 509 
Reflexes of dental origin, 500 
Refrigeration of pulp, 367 
Regeneration of blood-vessels, 87 
of epithelium, 88 
of tissues, 85 
Resorcin, 567 
Resorption, 61 
in dentition, 181 
of roots, failure in, 200 
Retzius, strise of, 125, 210 

in erosion, 253 
Ridge, dental, 106 
Robertson on caries, 265 
Robinson's remedy, 567 
Root, growth of, 118 
Root-apex, amputation of, 416 

-sheath of Hertwig, 118 
Roots, malformations of, 218 
perforated, amputation of, 427 
treatment of, 427 

SACCHARIN, 567 
Saliva, chemotactic property of, 49, 50 
composition of, 448 
deposits of calcium salts from, 449 
hypersecretion of, 450 
reaction of, 448 
toxicitv of, 513 
Salol, 568 
Salufer, 570 
Sandarac varnish, 570 
Saprophytic bacteria, 40 
Scaling teeth, 454 
Sohizomycetes, 38 
Sedation, effects of, 22 
Septic diseases of dental origin, 522 
infection, nature of, 90 
intoxication, 95 



INDEX. 



585 



Septic intoxication in children, 498 
Septicaemia, 96 

causes of, 97 

in dental abscess, 402 

symptoms of, 97 

treatment of, 98 

varieties of, 96 
Septico-pyaemia, 98 
Serres, glands of, 137 
Serum, blood-, germicidal power of, 50 
Sharpey, fibres of, in cementum, 136 
Sheaths of Neumann, 127 
Shellac varnish, 571 
Silico-fluorid of sodium, 570 
Silver citrate, 568, 569 

lactate, 569 

nitrate as astringent, 541 
decomposition of, 568 

tooth-staining by, 257 
Skiagraphy in diagnosis of impaction, 239 
Skin-eruption in teething, treatment of, 189 
Sodium bicarbonate, 569 

borate, 569. (See Borax also.) 

bromid, 553 

dioxid, 569 

reactions of, 536 

phenate, 569 

salicylate in gout, 488 

silico-fluorid, 570 

sulfite, 569 
Sozoiodol, 570 
Spirillae, 39 

Starch, synthesis of, 38 
Starches, effects of, in caries, 274 
Stellate reticulum, 112 

atrophy of, 115 
Steresol varnish, 571 
Sterilization, dental, 523 
of apparatus, 525 
of field of operation, 526 
of instruments, 525 
of operator, 524 
Stimulation, effects of, 21 
Stomatitis, aphthous, 516 

catarrhal infective, 514 

causes of, 513 

classification of, 514 

occurrence of, 513 

simple, treatment of, 514 

symptomatic, 515 

teething, 189, 190 

ulcerative, 515 
local, 516 

varieties of, 513 
Stratum granulosum, 118 

intermedium, 113 
Structural diseases, 24 
Struma, effects of, upon dentition, 194, 195 
Subgingival calculi, 452 
Suboxidation, diseases of, 445 
Sugar, fermentation of, 271 
Sulfo-methaemoglobin, 256 
Supernumerary teeth, 225 

origin of, 226 
Suppuration, 90 

causes of, 90 

leucocytosis in, 74 



Suppuration, prognosis of, 92 
symptoms of, 92 

general, 92 
treatment of, 92 
Syphilis, effects of, upon dentition, 194 
infective power of lesions, 518 
of mouth, primary, 519 
diagnosis of, 519 
mode of infection, 519 
secondary, 520 
sterilization, 527 
tertiary, 521 
stages of, 518 
Syphilitic affections of mouth, 518 
enamel, 211 
teeth, 219 

TEETH, abrasion of, 245 
treatment of, 246 
absence of, congenital, 224 
architectural designs of, 142 
calcic basis of, 113 
cleansing after scaling, 456 
concrescence of, 217 
deciduous, abrasion of, 493 
treatment of, 494 
canal-filling, 498 
caries of, 494 
cavity preparation in, 495 
deposits upon, 491 
destroying pulps of, 495 
diseases of, 491 

effects of premature loss of, 200 
extraction of, effects of, 220, 228 

delayed, effects of, 229 
green stains upon, 492 

importance of treating, 493 
pericementitis of, 498 
extraction for, 499 
treatment of, 498 
pulp-exposure in, 494 
treatment in, 495 
sensitivity of, 491 
pulps of, diseases of, 496 
removal of pulps of, 497 
silver nitrate in, 495 
defects of, and caries, 278 
deficiency in number of, 224 
disuse of, absolute, results of, 442 
pathology of, 443 
prognosis of, 443 
treatment of, 443 
partial, causes of, 441 
clinical history of, 441 
diagnosis of, 442 
pathology of, 441 
prognosis of, 442 
treatment of, 442 
dwarf, 215 
effects of eruptive fevers upon, 199 

of gestation upon, 276 
encysted, 231 
eruption of, 180 
causes of, 180 
process of, 181 
excess of, 225 
first evidence of formation, 105 



586 



INDEX. 



Teeth, fused, 216 
geminous, 217 
giantism of, 214 
gouty abscess upon, 485 

affections of, 483 
grinding of, in children, 494 

at night, 247 
grooved, 215 
honeycombed, 212 
Hutchinson, 128 
impacted, 231 
diagnosis of, 239 
symptoms of, 238 
treatment of, 240 
mal -occlusion of, causes of, 439 
diagnosis of, 440 
pathology of, 439 
prognosis of, 440 
treatment of, 440 
malpositions of, 227 
mechanical weakening of, 144 
nerves, plan of distribution of, 501 
overuse of, effects of, 437 
pathology of, 438 
treatment of, 438 
permanent, calcification of, 196 
development of, 119 

anatomical relations of, 196 
eruption of, 195 
origins of, 109 
resorption of roots of, 433 
causes of, 434 
morbid anatomy of, 433 
pathology of, 433 
symptoms of, 434 
treatment of, 435 
pitted, 215 
in pregnancy, 146 

primitive forms as abnormalities, 215 
relations of, 141 
resorption of temporary, 197 
sections of, 149, 150 
supernumerary, 225 
suppressed, 224 
surgical anatomy of, 141 
syphilitic, 219 

temporary, pulp-chambers of, 151, 152 
twin, 217 

upper, surgical relations of, 164 
Teething, 180 

gum-lancing in, 192, 193 
Teratomata, 56 
Thread-fungus, 511 
Thrombus, 72 

Thrush fungus, development of, 511 
Thymol, 565 
Tissues, nature of, 23 
Tomes on caries, 265 
fibres of, 129 
granular layer of, 147 
processes of, 147 
Toxalbumins, 43 
Toxicity of saliva, 513 
Treatment of alveolo-dental abscess, acute, 
402 
without fistula, 409 
on deciduous teeth, 498 



Treatment of alveolo-dental abscess, chronic, 
409, 411, 415 
by electrolysis, 415 
dental caries, 313 

erosion, 254 
disuse of teeth, absolute, 443 

partial, 442 
empyema of antrum, 418, 419 
fevers, 95 
gingivitis, 446, 447 
hypersemia, active, 78, 79 

passive, 80 
hypercementosis, 432, 433 
hypersensitive dentin, 308, 309, 310 
impacted teeth, 240 
inflammation, 84 
mal-occlusion, 440 
osteomyelitis, 95 
pathological dentition, 188-194 
pericementitis, general aseptic, 436 
of deciduous teeth, 498 
n on -septic apical, chronic, 421 
phagedenic, 474 
septic apical, chronic, 409-415 
traumatic, 426, 427 
perforated roots, 427 
pulp-exposure, 321 
deciduous teeth, 495 
gangrene, dry, 382 

moist, 387 
hypersemia, active, 345 

passive, 347 
hypertrophy, 366 
inflammation, 353 
-nodules, 339 
suppuration, 360 
pyaemia, 99 

pyorrhoea alveolaris, first class, 465-468 
resorption of permanent roots, 435 
salivary calculus, 454 
septicaemia, 98 
stomatitis, 514 
suppuration, 92 
ulceration, 93 
Trichlorphenol, 570 
Trikresol, 557 

Trismus, muscular, in dentition, 203 
Tropacocain, its chemical relations, 540 
Trophic nerves, 35 
Tubercle, nature of, 64 
Tuberculosis of mouth, 522 
Tubuli of dentin, 126 
Tumors, 54 
capsules of, 56 
causes of, 55 
classes of, 54, 55 
composition of, 55 
compound, 57 
degeneration of, 60 
effects of, 55 
epithelial, 59 
evolution of type, 57, 58 
fatty degeneration of, 64 
malignant, 56, 57 
recurrence of, 60 
benign, 56, 57 
Twin teeth, 217 



INDEX. 



587 



ULCEKATION, 93 
causes of, 93 
treatment of, 93 
Ulcers caused by jagged teeth, 246 
Urates, conditions of deposit, 481 
excess of, 250 
origin and effects of, 480 
Urea, effects of retained, 71 
Uric acid, origin of, 249-481 

T7ACCINATION, 32 
V effects of, upon teething, 189 
Varnishes, sandarac, 570 

shellac, 571 

steresol, 571 
Vascular system, disturbances of, 69 

range of, disturbances, 74 
Veratrina, 57.2 
Veratrum viride, 572 
Vitality, resistance of, 22 



Voluntary tooth-movement, 469 
WATTS on caries, 268 



X 



-KAY in diagnosis of impaction, 239 



ZINC chlorid, 572 
iodid, 572 
oxid, 573 
oxychlorid, 572 

properties of, 315, 573 
oxy sulfate, 573 

phosphate, properties oi, 315, 573 
sulfate, 573 
Zones of dentin in caries, 298 
transparent, in caries, 298 
Zooglea, 39 



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Library of Congress 
Branch Bindery, 1903 



